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Illustration creditsPage 52: Reprinted by permission from Macmillan Publishers Ltd: Nature Genetics, Albano Beja-Pereira, Gordon Luikart, Phillip R. England, Daniel G. Bradley,Oliver C. Jann, Giorgio Bertorelle, Andrew T. Chamberlain, Telmo P. Nunes, Stoitcho Metodiev, Nuno Ferrand, Georg Erhardt. “Gene-culture coevolution betweencattle milk protein genes and human lactase genes,” 35.4(2003) 311–313, copyright 2003. 91: Source: Benjamin Voight et al., “A Map of Recent Positive Selection inthe Human Genome,” PLoS Biology 4, 446–458 (2006). 132, 133, 135, 136, 137: Clark, Gregory, A Farewell to Alms. © 2007 by Princeton University Press.Reprinted by permission of Princeton University Press.

LIBRARY OF CONGRESS CATALOGING-IN-PUBLICATION DATA

Wade, NicholasA troublesome inheritance : genes, race and the rise of the West / Nicholas Wade.

pages cmIncludes bibliographical references and index.

ISBN 978-0-698-16379-91. Human evolution. 2. Sociobiology. 3. Race. 4. Civilization, Western. I. Title.

GN365.9.W33 2014599.93'8—dc23

2013040002

Version_1

CONTENTS

Title PageCopyright

1. EVOLUTION, RACE AND HISTORY

2. PERVERSIONS OF SCIENCE

3. ORIGINS OF HUMAN SOCIAL NATURE

4. THE HUMAN EXPERIMENT

5. THE GENETICS OF RACE

6. SOCIETIES AND INSTITUTIONS

7. THE RECASTING OF HUMAN NATURE

8. JEWISH ADAPTATIONS

9. THE RISE OF THE WEST

10. EVOLUTIONARY PERSPECTIVES ON RACE

AcknowledgmentsNotesIndex

S

1

EVOLUTION, RACE AND HISTORY

ince the decoding of the human genome in 2003, a sharp new light has been shed on humanevolution, raising many interesting but awkward questions.

It is now beyond doubt that human evolution is a continuous process that has proceededvigorously within the past 30,000 years and almost certainly—though very recent evolution

is hard to measure—throughout the historical period and up until the present day. It would be of thegreatest interest to know how people have evolved in recent times and to reconstruct the fingerprintsof natural selection as it molded and reworked the genetic clay. Any degree of evolution in socialbehavior found to have taken place during historical times could help explain significant features oftoday’s world.

But the exploration and discussion of these issues is complicated by the fact of race. Ever sincethe first modern humans dispersed from the ancestral homeland in northeast Africa some 50,000 yearsago, the populations on each continent have evolved largely independently of one another as eachadapted to its own regional environment. Under these various local pressures, there developed themajor races of humankind, those of Africans, East Asians and Europeans, as well as many smallergroups.

Because of these divisions in the human population, anyone interested in recent human evolutionis almost inevitably studying human races, whether they wish to or not. Scientific inquiry thus runsinto potential conflict with the public policy interest of not generating possibly invidious comparisonsthat might foment racism. Several of the intellectual barriers erected many years ago to combat racismnow stand in the way of studying the recent evolutionary past. These include the assumption that therehas been no recent human evolution and the assertion that races do not exist.

The New View of Human Evolution

New analyses of the human genome establish that human evolution has been recent, copious andregional. Biologists scanning the genome for evidence of natural selection have detected signals ofmany genes that have been favored by natural selection in the recent evolutionary past. No less than14% of the human genome, according to one estimate, has changed under this recent evolutionarypressure.1 Most of these signals of natural selection date from 30,000 to 5,000 years ago, just aneyeblink in evolution’s 3 billion year timescale.

Natural selection has continued to mold the human genome, doubtless up until the present day,although the signals of evolution within the past few hundred or thousand years are harder to pick upunless the force of selection has been extremely strong. One of the most recent known dates at which ahuman gene has been changed by evolution is from 3,000 years ago, when Tibetans evolved a geneticvariant that lets them live at high altitude.2

Several instances have now come to light of natural selection shaping human traits within just thepast few hundred years. Under the pressure of selection, for example, the age of first reproductionamong women born between 1799 and 1940 on L’Isle-aux-Coudres, an island in the Saint LawrenceRiver near Quebec, fell from 26 to 22 years, according to researchers who were able to study anunusually complete record of marriages, births and deaths in the island’s parish records.3

The researchers argue that other possible effects, like better nutrition, can be ruled out asexplanations, and note that the tendency to give birth at a younger age appeared to be heritable,confirming that a genetic change had taken place. “Our study supports the idea that humans are stillevolving,” they write. “It also demonstrates that microevolution is detectable over just a fewgenerations in a long-lived species.”

Another source of evidence for very recent human evolution is that of the multigenerationalsurveys conducted for medical reasons, like the Framingham Heart Study. Borrowing statisticalmethods developed by evolutionary biologists for measuring natural selection, physicians haverecently been able to tease out certain bodily changes that are under evolutionary pressure in theselarge patient populations. The traits include age at first reproduction, which is decreasing in modernsocieties, and age at menopause, which is increasing. The traits are of no particular importance inthemselves and have been measured just because the relevant data were collected by the physicianswho designed the studies. But the statistics suggest that the traits are inherited, and if so, they areevidence of evolution at work in present-day populations. “The evidence strongly suggests that weare evolving and that our nature is dynamic, not static,” a Yale biologist, Stephen Stearns, concludesin summarizing 14 recent studies that measured evolutionary change in living populations.4

Human evolution has not only been recent and extensive; it has also been regional. The period of30,000 to 5,000 years ago, from which signals of recent natural selection can be detected, occurredafter the splitting of the three major races, and so represents selection that has occurred largelyindependently within each race. The three principal races are Africans (those who live south of theSahara), East Asians (Chinese, Japanese and Koreans) and Caucasians (Europeans and the peoples ofthe Near East and the Indian subcontinent). In each of these races, a different set of genes has beenchanged by natural selection, as is described further in chapter 5. This is just what would be expectedfor populations that had to adapt to different challenges on each continent. The genes specially

affected by natural selection control not only expected traits like skin color and nutritionalmetabolism but also some aspects of brain function, although in ways that are not yet understood.

Analysis of genomes from around the world establishes that there is indeed a biological reality torace, despite the official statements to the contrary of leading social science organizations. A longerdiscussion of this issue is offered in chapter 5, but an illustration of the point is the fact that withmixed-race populations, such as African Americans, geneticists can now track along an individual’sgenome and assign each segment to an African or European ancestor, an exercise that would beimpossible if race did not have some basis in biological reality.

The fact that human evolution has been recent, copious and regional is not widely recognized,even though it has now been reported by many articles in the literature of genetics. The reason is inpart that the knowledge is so new and in part because it raises awkward challenges to deeply heldconventional wisdom.

The Social Science Creed and Evolution

It has long been convenient for social scientists to assume that human evolution ground to a halt in thedistant past, perhaps when people first learned to put a roof over their heads and to protectthemselves from the hostile forces of nature. Evolutionary psychologists teach that the human mind isadapted to the conditions that prevailed at the end of the last age, some 10,000 years ago. Historians,economists, anthropologists and sociologists assume there has been no change in innate humanbehavior during the historical period.

This belief in the recent suspension of evolution, at least for people, is shared by the majorassociations of social scientists, which assert that race does not even exist, at least in the biologicalsense. “Race is a recent human invention,” proclaims the American Anthropological Association.“Race is about culture, not biology.” 5 A recent book published by the association states that “Race isnot real in the way we think of it: as deep, primordial, and biological. Rather it is a foundational ideawith devastating consequences because we, through our history and culture, made it so.” 6

The commonsense conclusion—that race is both a biological reality and a politically fraught ideawith sometimes pernicious consequences—has also eluded the American Sociological Association.The group states that “race is a social construct” and warns “of the danger of contributing to thepopular conception of race as biological.” 7

The social scientists’ official view of race is designed to support the political view that geneticscannot possibly be the reason why human societies differ—the answer must lie exclusively indiffering human cultures and the environment that produced them. The social anthropologist FranzBoas established the doctrine that human behavior is shaped only by culture and that no culture issuperior to any other. From this point of view it follows that all humans are essentiallyinterchangeable apart from their cultures, and that more complex societies owe their greater strengthor prosperity solely to fortunate accidents such as that of geography.

The recent discoveries that human evolution has been recent, copious and regional severelyundercut the social scientists’ official view of the world because they establish that genetics mayhave played a possibly substantial role alongside culture in shaping the differences between humanpopulations. Why then do many researchers still cling to the notion that culture alone is the onlypossible explanation for the differences between human societies?

One reason is, of course, the understandable fear that exploration of racial differences will givesupport to racism, a question addressed below. Another is the inherent inertia of the academic world.University researchers do not act independently but rather as communities of scholars who constantlycheck and approve one another’s work. This is especially so in science, where grant applicationsmust be approved by a panel of peers, and publications submitted to the scrutiny of editors andreviewers. The high advantage of this process is that the statements scholars make in public areusually a lot more than their own opinion—they are the certified knowledge of a community ofexperts.

But a drawback of the system is its occasional drift toward extreme conservatism. Researchersget attached to the view of their field they grew up with and, as they grow older, they may gain theinfluence to thwart change. For 50 years after it was first proposed, leading geophysicists strenuouslyresisted the idea that the continents have drifted across the face of the globe. “Knowledge advances,

funeral by funeral,” the economist Paul Samuelson once observed.Another kind of flaw occurs when universities allow a whole field of scholars to drift politically

to the left or to the right. Either direction is equally injurious to the truth, but at present mostuniversity departments lean strongly to the left. Any researcher who even discusses issues politicallyoffensive to the left runs the risk of antagonizing the professional colleagues who must approve hisrequests for government funds and review his articles for publication. Self-censorship is the frequentresponse, especially in anything to do with the recent differential evolution of the human population. Ittakes only a few vigilantes to cow the whole campus. The result is that researchers at presentroutinely ignore the biology of race, or tiptoe around the subject, lest they be accused of racism bytheir academic rivals and see their careers destroyed.

Resistance to the idea that human evolution is recent, copious and regional is unlikely to vanishunless scholars can be persuaded that exploration of the recent evolutionary past will not lead to aresurgence of racism. In fact, such a resurgence seems most unlikely, for the following reasons.

Genomics and Racial Differences

In the first place, opposition to racism is now well entrenched, at least in the Western world. It ishard to conceive of any circumstance that would reverse or weaken this judgment, particularly anyscientific evidence. Racism and discrimination are wrong as a matter of principle, not of science.Science is about what is, not what ought to be. Its shifting sands do not support values, so it is foolishto place them there.

Academics, who are obsessed with intelligence, fear the discovery of a gene that will prove onemajor race is more intelligent than another. But that is unlikely to happen anytime soon. Althoughintelligence has a genetic basis, no genetic variants that enhance intelligence have yet been found. Thereason, almost certainly, is that there are a great many such genes, each of which has too small aneffect to be detectable with present methods.8 If researchers should one day find a gene that enhancesintelligence in East Asians, say, they can hardly argue on that basis that East Asians are moreintelligent than other races, because hundreds of similar genes remain to be discovered in Europeansand Africans.

Even if all the intelligence-enhancing variants in each race had been identified, no one would tryto compute intelligence on the basis of genetic information: it would be far easier just to apply anintelligence test. But IQ tests already exist, for what they may be worth.

Even if it were proved that one race were genetically more intelligent than another, whatconsequence would follow? In fact, not much of one. East Asians score around 105 on intelligencetests, an average above that of Europeans, whose score is 100. A higher IQ score doesn’t make EastAsians morally superior to other races. East Asian societies have many virtues but are not necessarilymore successful than European societies in meeting their members’ needs.

The notion that any race has the right to dominate others or is superior in any absolute sense canbe firmly rejected as a matter of principle and, being rooted in principle, is unassailable by science.Nonetheless, races being different, it is inevitable that science will establish relative advantages insome traits. Because of genetic variants, Tibetans and Andean highlanders are better than others atliving at high altitudes. At every Olympic games since 1980, every finalist in the men’s 100-meterrace has had West African ancestry.9 It would be no surprise if some genetic factor were found tocontribute to such athleticism.

Study of the genetics of race will inevitably reveal differences, some of which will show, forthose who may be interested, that one race has some slight edge over another in a specified trait. Butthis kind of inquiry will also establish a wider and more important truth, that all differences betweenraces are variations on a common theme.

To discover that genetics plays some role in the differences between the major human societiesdoes not mean that that role is dominant. Genes do not determine human behavior; they merelypredispose people to act in certain ways. Genes explain a lot, probably far more than is at presentunderstood or acknowledged. But their influence in most situations is or can be overwhelmed bylearned behavior, or culture. To say that genes explain everything about human social behavior wouldbe as absurd as to assume that they explain nothing.

Social scientists often write as if they believe that culture explains everything and race nothing,and that all cultures are of equal value. The emerging truth is more complicated. Human nature is very

similar throughout the world. But though people are much the same, their societies differ greatly intheir structure, their institutions and their achievements. Contrary to the central belief ofmulticulturalists, Western culture has achieved far more than other cultures in many significantspheres and has done so because Europeans, probably for reasons of both evolution and history, havebeen able to create open and innovative societies, starkly different from the default humanarrangements of tribalism or autocracy. People being so similar, no one has the right or reason toassert superiority over a person of a different race. But some societies have achieved much more thanothers, perhaps through minor differences in social behavior. A question to be explored below iswhether such differences have been shaped by evolution.

Social Behavior and History

The purpose of the pages that follow is to demystify the genetic basis of race and to ask what recenthuman evolution reveals about history and the nature of human societies. If fear of racism can beovercome sufficiently for researchers to accept that human evolution has been recent, copious andregional, a number of critical issues in history and economics may be laid open for exploration. Racemay be a troublesome inheritance, but better to explore and understand its bearing on human natureand history than to pretend for reasons of political convenience that it has no evolutionary basis.

It’s social behavior that is of relevance for understanding pivotal—and otherwise imperfectlyexplained—events in history and economics. Although the emotional and intellectual differencesbetween the world’s peoples as individuals are slight enough, even a small shift in social behaviorcan generate a very different kind of society. Tribal societies, for instance, are organized on the basisof kinship and differ from modern states chiefly in that people’s radius of trust does not extend too farbeyond the family and tribe. But in this small variation is rooted the vast difference in political andeconomic structures between tribal and modern societies. Variations in another genetically basedbehavior, the readiness to punish those who violate social rules, may explain why some societies aremore conformist than others.

Social structure is the point at which human evolution intersects with history. Vast changes haveoccurred in human social structure in all three major races within the past 15,000 years. That is theperiod in which people first started to switch from the nomadic life of hunter-gatherer bands to settledexistence in much larger communities. This wrenching shift required living in a hierarchical societyinstead of an egalitarian one and the temperament to get on with many strangers instead of just a fewclose kin. Given that this change took so long to occur—modern humans first appear in thearchaeological record 200,000 years ago, yet it took them 185,000 years to settle down in fixedcommunities—it is tempting to assume that a substantial genetic change in social behavior wasrequired and that it took this long to evolve. Moreover, this evolutionary process took placeindependently in the populations of Europe, East Asia, the Americas and Africa, which had separatedlong before the first settlements emerged.

The forager-settler transition is unlikely to have been the only evolutionary change in humansocial behavior. Probably from the beginning of agriculture some 10,000 years ago, most people havelived on the edge of starvation. After each new increase in productivity, more babies were born, theextra mouths ate up the surplus and within a generation everyone was back to a state of scarcity littlebetter than before.

This situation was accurately described by the Reverend Thomas Malthus with his analysis thatpopulation was always kept in check by misery and vice. It was from Malthus that Darwin derivedthe idea of natural selection. Under conditions of the fierce struggle for existence that Malthusdescribed, favorable variations would be preserved, Darwin perceived, and unfavorable onesdestroyed, leading eventually to the formation of new species.

Given that the human population supplied Malthus with the observations that led Darwin to theconcept of natural selection, there is every reason to suppose that people living in agrarian societieswere subject to intense forces of natural selection. But what traits were being selected for during thelong agrarian past? Evidence described in chapter 7 indicates that it was human social nature that

changed. Until the great demographic transition that followed industrialization, the wealthy had moresurviving children than the poor. As many of the children of the rich fell in status, they would havespread throughout the population the genes that support the behaviors useful in accumulating wealth.This ratchet of wealth provides a general mechanism for making a specific set of behaviors—thoserequired for economic success—more general and, generation after generation, gradually changing asociety’s nature. The mechanism has so far been documented only for a population for whichunusually precise records exist, that of England from 1200 to 1800. But given the strong humanpropensity for investing in one’s children’s success, the ratchet may well have operated in allsocieties in which there have been gradations of wealth.

The narratives constructed by historians describe many forms of change, whether political,military, economic or social. One factor almost always assumed to be constant is human nature. Yet ifhuman social nature, and therefore the nature of human societies, has changed in the recent past, a newvariable is available to help explain major turning points in history. The Industrial Revolution, forinstance, marked a profound change in the productivity of human societies, one that took almost15,000 years to emerge after the first settlements. Could this too have required the evolution of adifference in human social behavior, as significant as the one that accompanied the transition fromforaging to settled life?

There are other significant turning points in history for which scholars have proposed a clutch ofpossible causes but no compelling explanation. China created the first modern state and enjoyed themost advanced civilization until around 1800 AD, when it slid into puzzling decline. The Islamicworld in 1500 AD surpassed the West in most respects, reaching a high tide of its expansion in thesiege of Vienna in 1529 AD by the forces of the Ottoman Sultan Suleiman the Magnificent. Then, afteralmost a thousand years of relentless conquest, the house of Islam entered a long and painful retreat,also for reasons that defy scholarly consensus.

The counterpart of Chinese and Islamic decline is the unexpected rise of the West. Europe, feudaland semitribal in 1000 AD, had become a vigorous exponent of learning and exploration by 1500 AD.From this basis, Western nations seized the lead in geographical expansion, in military preeminence,in economic prosperity and in science and technology.

Economists and historians have described many factors that contributed to Europe’s awakening.One that is seldom considered is the possibility of an evolutionary change, that the Europeanpopulation, in adapting to its particular local circumstances, happened to evolve a kind of society thatwas highly favorable to innovation.

Economic Disparities

Explanation is also lacking for many important features of even today’s world. Why are somecountries rich and others persistently poor? Capital and information flow fairly freely, so what is itthat prevents poor countries from taking out a loan, copying every Scandinavian institution, andbecoming as rich and peaceful as Denmark? Africa has absorbed billions of dollars in aid over thepast half century and yet, until a recent spurt of growth, its standard of living has stagnated fordecades. South Korea and Taiwan, on the other hand, almost as poor at the start of the period, haveenjoyed an economic resurgence. Why have these countries been able to modernize so rapidly whileothers have found it much harder?

Economists and historians attribute the major disparities between countries to factors such asresources or geography or cultural differences. But many countries with no resources, like Japan orSingapore, are very rich, while richly endowed countries like Nigeria tend to be quite poor. Iceland,covered mostly in glaciers and frigid deserts, might seem less favorably situated than Haiti, butIcelanders are wealthy and Haitians beset by persistent poverty and corruption. True, cultureprovides a compelling and sufficient explanation for many such differences. In the natural experimentprovided by the two Koreas, the people are the same in both countries, so it must surely be badinstitutions that keep North Koreans poor and good ones that make South Koreans prosperous.

But in situations where culture and political institutions can flow freely across borders, longenduring disparities are harder to explain. The brisk and continuing pace of human evolution suggestsa new possibility: that at the root of each civilization is a particular set of evolved social behaviorsthat sustains it, and these behaviors are reflected in the society’s institutions. Institutions are not justsets of arbitrary rules. Rather, they grow out of instinctual social behaviors, such as the propensity totrust others, to follow rules and punish those who don’t, to engage in reciprocity and trade, or to takeup arms against neighboring groups. Because these behaviors vary slightly from one society to thenext as the result of evolutionary pressures, so too may the institutions that depend on them.

This would explain why it is so hard to transfer institutions from one society to another. Americaninstitutions cannot be successfully implanted in Iraq, for instance, because Iraqis have different socialbehaviors, including a base in tribalism and a well-founded distrust of central government, just as itwould be impossible to import Iraqi tribal politics into the United States.

With the advent of fast and cheap methods for decoding the sequence of DNA units in the humangenome, the genetic variations that underlie human races can be explored for the first time. Theevolutionary paths that have generated differences between races are of great interest to researchersand many are described in the pages that follow. But the broader significance of the worldwidevariations in DNA is not the differences but the similarities. Nowhere is the essential unity ofhumankind more clearly and indelibly written than in the human genome.

• • •

Since much of the material that follows may be new or unfamiliar to the general reader, a guide to itsevidentiary status may be helpful. Chapters 4 and 5, which explore the genetics of race, are probably

the most securely based. Although they put the reader on the forefront of current research, and frontierscience is always more prone to upset than that in the textbooks, the findings reported here draw froma large body of research by leading experts in the field and seem unlikely to be revised in any seriousway. Readers can probably take the facts in these chapters as reasonably solid and the interpretationsas being in general well supported.

The discussion of the roots of human social behavior in chapter 3 also rests on substantialresearch, in this case mostly studies of human and animal behavior. But the genetic underpinnings ofhuman social behavior are for the most part still unknown. There is therefore considerable room fordisagreement as to exactly which social behaviors have a genetic basis and how strongly any suchbehaviors may be genetically defined. Moreover the whole field of research into human socialbehavior is both young and overshadowed by the paradigm still influential among social scientiststhat all human behavior is purely cultural.

Readers should be fully aware that in chapters 6 through 10 they are leaving the world of hardscience and entering into a much more speculative arena at the interface of history, economics andhuman evolution. Because the existence of race has long been ignored or denied by many researchers,there is a dearth of factual information as to how race impinges on human society. The conclusionspresented in these chapters fall far short of proof. However plausible (or otherwise) they may seem,many are speculative. There is nothing wrong with speculation, of course, as long as its premises aremade clear. And speculation is the customary way to begin the exploration of uncharted territorybecause it stimulates a search for the evidence that will support or refute it.

I

2

PERVERSIONS OF SCIENCE

Imperialists, calling upon Darwinism in defense of the subjugation of weaker races, could point to The Originof Species, which referred in its subtitle to The Preservation of Favored Races in the Struggle for Life.Darwin had been talking about pigeons, but the imperialists saw no reason why his theories should not applyto men.

—RICHARD HOFSTADTER1

deas about race, many of them generated by biologists, have been exploited to justify slavery, tosterilize people deemed unfit and, in Hitler’s Germany, to conduct murderous campaigns againstinnocent and defenseless segments of society such as Gypsies, homosexuals and mentally illchildren. Most chilling of all was the horrific fusion of eugenic ideas with notions of racial

purity that drove the National Socialists to slaughter some 6 million Jews in the territories under theircontrol.

Because there could be no more serious caution for any who would inquire into the nature of race,the errors that lured people and governments down these mistaken paths need first to be understood.

Racism is a surprisingly modern concept, the word first appearing in the Oxford EnglishDictionary only in 1910. Before that, ethnic prejudice existed in profusion and still does. The ancientGreeks applied the word barbarian to anyone who didn’t speak Greek. China has long called itselfthe Central Kingdom, regarding as barbarians all who live outside its borders. The click-speakingbushmen of the Kalahari Desert divide the world into Ju|’hoansi, or “real people,” such asthemselves, and !ohm, a category that includes other Africans, Europeans and inedible animals suchas predators. Europeans link nationality with edibility in devising derogatory names for one another.Thus the French refer to the English as les rosbifs (“roast beefs”), while the English call the Frenchfrogs (as in frogs’ legs, a French delicacy) and Germans krauts (from sauerkraut, or fermentedcabbage).

The central premise of racism, which distinguishes it from ethnic prejudice, is the notion of anordered hierarchy of races in which some are superior to others. The superior race is assumed toenjoy the right to rule others because of its inherent qualities.

Besides superiority, racism also connotes the idea of immutability, thought once to reside in theblood and now in the genes. Racists are concerned about intermarriage (“the purity of the blood”) lestit erode the basis of their race’s superiority. Since quality is seen as biologically inherent, the racist’shigher status can never be challenged, and inferior races can never redeem themselves. The notion ofinherent superiority, which is generally absent from mere ethnic prejudice, is held to justify unlimitedabuse of races held to be inferior, from social discrimination to annihilation. “The essence of racism

is that it regards individuals as superior or inferior because they are imagined to share physical,mental and moral attributes with the group to which they are deemed to belong, and it is assumed thatthey cannot change these traits individually,” writes the historian Benjamin Isaac.2

It’s not surprising that the notion of racial superiority emerged in the 19th century, after Europeannations had established colonies in much of the world and sought a theoretical justification of theirdominion over others.

At least two other strands of thought fed into modern ideologies of racism. One was the effort byscientists to classify the many human populations that European explorers were able to describe. Theother was that of Social Darwinism and eugenics.

Classifying Human Races

In the 18th century Linnaeus, the great classifier of the world’s organisms, recognized four races,based principally on geography and skin color. He named them Homo americanus (NativeAmericans), Homo europaeus (Europeans), Homo asiaticus (East Asians) and Homo afer(Africans). Linnaeus did not perceive a hierarchy of races, and he listed people alongside the rest ofnature.

In a 1795 treatise called On the Natural Variety of Mankind, the anthropologist JohannBlumenbach described five races based on skull type. He added a Malay race, essentially people ofMalaya and Indonesia, to Linnaeus’s four, and he invented the useful word Caucasian to denote thepeoples of Europe, North Africa and the Indian subcontinent. The origin of the name was due in partto his belief that the people of Georgia, in the southern Caucasus, were the most beautiful and in partto the then prevailing view that Noah’s ark had set down on Mount Ararat in the Caucasus, making theregion the homeland of the first people to colonize the earth.

Blumenbach has been unjustly tarred with the supremacist beliefs of his successors. In fact heopposed the idea that some races were superior to others, and he conceded that his appraisal ofCaucasian comeliness was subjective.3 His views on Caucasian beauty can more reasonably beascribed to ethnic prejudice than to racism. Moreover Blumenbach insisted that all humans belongedto the same species, as against the view then emerging that the human races were so different fromone another as to constitute different species.

Up until Blumenbach, the study of human races was a reasonably scientific attempt to understandand explain human variation. The more dubious turn taken in the 19th century was exemplified byJoseph-Arthur Comte de Gobineau’s book An Essay on the Inequality of Human Races, published in1853–55. Gobineau was a French aristocrat and diplomat, not a scientist, and a friend andcorrespondent of de Tocqueville. His book was a philosophical attempt to explain the rise and fall ofnations, based essentially on the idea of racial purity. He assumed there were three races recognizedby the skin colors of white, yellow and black. A pure race might conquer its neighbors, but as itinterbred with them, it would lose its edge and risk being conquered in turn. The reason, Gobineausupposed, was that interbreeding leads to degeneracy.

The superior race, Gobineau wrote, was that of the Indo-Europeans, or Aryans, and theircontinuance in the Greek, Roman and European empires. Contrary to what might be expected fromHitler’s exploitation of his works, Gobineau greatly admired Jews, whom he described as “a peoplethat succeeded in everything it undertook, a free, strong, and intelligent people, and one which, beforeit lost, sword in hand, the name of an independent nation, had given as many learned men to the worldas it had merchants.”

Gobineau’s ambitious theory of history was built on sand. There is no factual basis for his notionsof racial purity or racial degeneration through interbreeding. His ideas would doubtless have beenforgotten but for the pernicious theme of an Aryan master race. Hitler adopted this worthless conceptwhile ignoring Gobineau’s considerably more defensible observations about Jews.

To Gobineau’s assertion of inequality between races was then added the divisive idea that thevarious human populations represented not just different races but also different species. A leadingproponent of this belief was the Philadelphia physician Samuel Morton.

Morton’s views were driven into error not by prejudice but by his religious faith. He wastroubled by the fact that black and white people were depicted in Egyptian art from 3000 BC yet theworld itself had been created only in 4004 BC, according to the widely accepted chronology drawn upby Archbishop Ussher from information derived from the Old Testament and elsewhere. This was notenough time for different races to emerge, so the races must have been created separately, Mortonargued, a valid inference if Ussher’s chronology had been even remotely correct.

Morton amassed a large collection of skulls from all over the world, measuring the volumeoccupied by the brain and other details that in his view established the distinctness of the fourprincipal races. He effectively ranked them in a hierarchy by adding subjective descriptions of eachrace’s behavior to his careful anatomical measurements of their skulls. Europeans are the earth’s“fairest inhabitants,” he wrote. Next were Mongolians, meaning East Asians, deemed “ingenious,imitative and highly susceptible of cultivation.” Third place was assigned to Americans, meaningNative Americans, whose mental faculties appeared to Morton as locked in a “continual childhood,”and fourth were Negroes, or Africans, who Morton said “have little invention, but strong powers ofimitation, so that they readily acquire mechanic arts.”

Morton was an academic and did not promote any practical consequences of his ideas. But hisfollowers had no hesitation in spelling out their interpretation that the races had been createdseparately, that blacks were inferior to whites and that the slavery of the American South wastherefore justified.

Morton’s data present an interesting case study of how a scientist’s preconceptions can affect hisresults, despite the emphasis in scientific training on the critical importance of objectivity. TheHarvard biologist Stephen Jay Gould, a widely read essayist, accused Morton of having mismeasuredthe cranial volumes of African and Caucasian skulls in order to support the view that brain size isrelated to intelligence. Gould didn’t remeasure Morton’s skulls, but he recomputed Morton’spublished statistical analysis and estimated that all four races had skull volumes of about the samesize. Gould’s accusations were published in Science and in his widely cited 1981 book TheMismeasure of Man.

But in a surprising recent twist, the bias now turns out to have been Gould’s. Morton did not infact believe, as Gould asserted, that intelligence was correlated with brain size. Rather, he wasmeasuring his skulls to study human variation as part of his inquiry into whether God had created thehuman races separately. A team of physical anthropologists remeasured all of the skulls they couldidentify in Morton’s collection and found his measurements were almost invariably correct. It wasGould’s statistics that were in error, they reported, and the errors lay in the direction of supportingGould’s incorrect belief that there was no difference in cranial capacity between Morton’s groups.“Ironically, Gould’s own analysis of Morton is likely the stronger example of a bias influencingresults,” the Pennsylvania team wrote.4

The authors noted that “Morton, in the hands of Stephen Jay Gould, has served for 30 years as atextbook example of scientific misconduct.” Moreover Gould had suggested that science as a whole isan imperfect process because bias such as Morton’s is common. This, the authors suggested, isincorrect: “The Morton case, rather than illustrating the ubiquity of bias, instead shows the ability ofscience to escape the bounds and blinders of cultural contexts.”

There are two lessons to be drawn from the Morton-Gould imbroglio. One is that scientists,despite their training to be objective observers, are as fallible as anyone else when their emotions or

politics are involved, whether they come from the right or, as in Gould’s case, from the left.A second is that, despite the personal failings of some scientists, science as a knowledge-

generating system does tend to correct itself, though often only after considerable delay. It is duringthese delay periods that great harm can be caused by those who use uncorrected scientific findings topropagate injurious policies. Scientists’ attempts to classify human races and to understand the properscope of eugenics were both hijacked before the two fields could be fully corrected.

A firm refutation of the idea that human races were different species was supplied by Darwin. InOn the Origin of Species, published in 1859, he laid out his theory of evolution but, perhapspreferring to take one step at a time, said nothing in particular about the human species. Humans werecovered in his second volume, The Descent of Man, which appeared 12 years later. With his unerringgood sense and insight, Darwin decreed that the human races, however distinct they might appear,were not nearly different enough to be considered separate species, as the followers of SamuelMorton and others were contending.

He started out by observing that “if a naturalist, who had never before seen a Negro, Hottentot,Australian or Mongolian, were to compare them . . . he would assuredly declare that they were asgood species as many to which he had been in the habit of affixing specific names.”

In support of such a view (Darwin is making the best contrary case before he knocks it down), henoted that the various human races are fed on by different kinds of lice. “The surgeon of a whalingship in the Pacific”—Darwin had a far-flung network of informants—“assured me that when thePediculi, with which some Sandwich Islanders on board swarmed, strayed onto the bodies of theEnglish sailors, they died in the course of three or four days.” So if the parasites on human races aredistinct species, it “might fairly be urged as an argument that the races themselves ought to beclassified as distinct species,” Darwin suggested.

On the other hand, whenever two human races occupy the same area, they interbreed, Darwinnoted. Also, the distinctive traits of each race are highly variable. Darwin cited the example of theextended labia minora (“Hottentot apron”) of bushmen women. Some women have the apron, but notall do.

The strongest argument against treating the races of men as separate species, in Darwin’s view,“is that they graduate into each other, independently in many cases, as far as we can judge, of theirhaving intercrossed.” This graduation is so extensive that people trying to enumerate the number ofhuman races were all over the map in their estimates, which ranged from 1 to 63, Darwin noted. Butevery naturalist trying to describe a group of highly varying organisms will do well to unite them intoa single species, Darwin observed, for “he has no right to give names to objects which he cannotdefine.”

Anyone reading works of anthropology can hardly fail to be impressed by the similaritiesbetween the races. Darwin noted “the pleasure which they all take in dancing, rude music, acting,painting, tattooing and otherwise decorating themselves; in their mutual comprehension of gesture-language, by the same expression in their features, and by the same inarticulate cries, when excited bythe same emotions.” When the principle of evolution is accepted, “as it surely will be before long,”Darwin wrote hopefully, the dispute as to whether humans belong to a single species or many “willdie a silent and unobserved death.”

Social Darwinism and Eugenics

Darwin, by force of his authority, could put the idea of many human species to rest. Despite his bestefforts, he had less success in throttling the political movement called Social Darwinism. This wasthe proposition that just as in nature the fittest survive and the weak are pushed to the wall, the samerule should prevail in human societies too, lest nations be debilitated by the poor and sick having toomany children.

The promoter of this idea was not Darwin but the English philosopher Herbert Spencer. Spencerdeveloped a theory about the evolution of society, which held that ethical progress depended onpeople adapting to current conditions. The theory was developed independently of Darwin’s andlacked any of the extensive biological research on which Darwin’s was based. Still, it was Spencerwho coined the phrase “survival of the fittest,” which Darwin adopted.

Spencer argued that government aid that would allow the poor and sickly to propagate wouldimpede society’s adaptation. Even government support for education should be cut off, lest itpostpone the elimination of those who failed to adapt. Spencer was one of the most prominentintellectuals of the second half of the 19th century, and his ideas, however harsh they may seem today,were widely discussed in both Europe and America.

Darwin’s theory of evolution, at least in its author’s eyes, dealt solely with the natural world. Yetit was as attractive to political theorists as a candle’s flame is to moths. Karl Marx asked if he coulddedicate Das Kapital to Darwin, an honor the great naturalist declined.5 Darwin’s name was slappedon to Spencer’s political ideas, which would far more accurately have been called SocialSpencerism. Darwin himself demolished them in a lapidary reproof.

Yes, vaccination has saved millions whose weaker constitutions would otherwise have let themsuccumb to smallpox, Darwin wrote. And yes, the weak members of civilized societies propagatetheir kind, which, to judge from animal breeding, “must be highly injurious to the race of man.” Butthe aid we feel impelled to give to the helpless is part of our social instincts, Darwin said. “Norcould we check our sympathy, even at the urging of hard reason, without deterioration in the noblestpart of our nature,” he wrote. “If we were intentionally to neglect the weak and helpless, it could onlybe for a contingent benefit, with an overwhelming present evil.” 6

Had Darwin’s advice been heeded, a disastrous turn in 20th century history might have beensomewhat less inevitable. But for many intellectuals, theoretical benefits often outweighoverwhelming present evils. Airy notions of racial improvement drove the eugenics movement, whichover many decades created the mental climate for the mass exterminations conducted by the NationalSocialists in Germany. Yet this catastrophe started out in such a different place. It started withDarwin’s cousin, Francis Galton.

Galton was a Victorian gentleman and polymath who made distinguished contributions to manyfields of science. He invented several basic statistical techniques, such as the concepts of correlation,regression and standard deviation. He anticipated human behavior genetics by using twins to sort outthe influences of nature and nurture. He devised the classification scheme still used in fingerprintidentification. He drew the first weather map. Mischievously wondering how to test if prayers wereanswered, he noted that the English population had for centuries prayed each week in church for thelong life of their sovereign, so that if prayer had any power at all, it should surely result in the greater

longevity of English monarchs. His report that sovereigns were the shortest-lived of all rich peopleand hence that prayer had no positive effect was rejected by an editor as “too terribly conclusive andoffensive not to raise a hornet’s nest” and lay unpublished for many years.7

One of Galton’s principal interests was that of whether human abilities are hereditary. Hecompiled various lists of eminent people and looked for those who were related to one another.Within these families, he found that close relatives of the founder were more likely to be eminent thandistant ones, establishing that intellectual distinction had a hereditary basis.

Galton was compelled by contemporary critics to pay more attention to the fact that the childrenof eminent men had greater educational and other opportunities than others. He conceded that nurturewas involved to some extent, even inventing the phrase “nature versus nurture” in doing so. But hisinterest in the inheritance of outstanding abilities remained. Darwin’s theory of evolution was nowwidely accepted in England and Galton, with his avidity for measuring human traits, was interested inthe effect of natural selection on the English population.

This line of thought now led him down a dangerous path, to the proposal that human populationscould be improved by controlled breeding, just like those of domestic animals. His finding thateminence ran in families led him to propose that marriages between such families should beencouraged with monetary incentives so as to improve the race. For this goal, Galton coined anotherword, eugenics.

In an unpublished novel, “Kantsaywhere,” Galton wrote that those who failed eugenic tests wereto be confined to camps where they had to work hard and remain celibate. But this seems to havebeen mostly a thought experiment or fantasy in Galton’s mind. In his published work, he emphasizedpublic education about eugenics and positive incentives for marriage among the eugenically fit.

There is no particular reason to doubt the assessment of one of Galton’s biographers, NicholasGillham, that Galton “would have been horrified had he known that within little more than 20 years ofhis death forcible sterilization and murder would be carried out in the name of eugenics.” 8

Galton’s ideas seemed reasonable at the time, given the knowledge of the day. Natural selectionseemed to have loosened its grip on modern populations. Birth rates at the end of the 19th centurywere in decline, particularly sharply among the upper and middle classes. It seemed logical enoughthat the quality of the population would be improved if the upper classes could be encouraged to havemore children. Galton’s ideas were favorably received. Honors flowed in. He was awarded theDarwin Medal of the Royal Society, England’s preeminent scientific institution. In 1908, three yearsbefore his death, he received a knighthood, a mark of establishment approval. No one then understoodthat he had unwittingly sown the dragon’s teeth.

The lure of Galton’s eugenics was his belief that society would be better off if the intellectuallyeminent could be encouraged to have more children. What scholar could disagree with that? More ofa good thing must surely be better. In fact it is far from certain that this would be a desirable outcome.Intellectuals as a class are notoriously prone to fine-sounding theoretical schemes that lead tocatastrophe, such as Social Darwinism, Marxism or indeed eugenics.

By analogy with animal breeding, people could no doubt be bred, if it were ethically acceptable,so as to enhance specific desired traits. But it is impossible to know what traits would benefit societyas a whole. The eugenics program, however reasonable it might seem, was basically incoherent.

And in terms of practicalities, it held a fatal diversion. Galton’s idea of eugenics was to inducethe rich and middle class to change their marriage habits and bear more children. But positive

eugenics, as such a proposal is known, was a political nonstarter. Negative eugenics, the segregationor sterilization of those deemed unfit, was much easier to put into practice.

In 1900 Mendel’s laws of genetics, ignored in his lifetime, were rediscovered. Geneticists, bycombining his laws with the statistical methods developed by Galton and others, started to developthe powerful subdiscipline known as population genetics. Leading geneticists on both sides of theAtlantic used their newfound authority to promote eugenic ideas. In doing so, they unleashed an ideawhose deeply malignant powers they proved unable to control.

The principal organizer of the new eugenics movement was Charles Davenport. He earned adoctorate in biology from Harvard and taught zoology at Harvard, the University of Chicago, and theBrooklyn Institute of Arts and Sciences Biological Laboratory at Cold Spring Harbor on Long Island.Davenport’s views on eugenics were motivated by disdain for races other than his own: “Can webuild a wall high enough around this country so as to keep out these cheaper races, or will it be afeeble dam . . . leaving it to our descendants to abandon the country to the blacks, browns and yellowsand seek an asylum in New Zealand?” he wrote.9

A heavy wave of immigrants arrived in the United States between 1890 and 1920, creating aclimate of concern that was favorable for eugenic ideas. Davenport, though he had no specialdistinction as a scientist, found it easy to raise money for his eugenics program. He secured fundsfrom leading philanthropies, such as the Rockefeller Foundation and the recently founded CarnegieInstitution. Scouring a list of wealthy families on Long Island, he came across the name of MaryHarriman, daughter of the railroad magnate E. H. Harriman. Mary, as it happened, was so interestedin eugenics that her nickname in college had been Eugenia. She provided Davenport funds to set uphis Eugenics Record Office, which was intended to register the genetic backgrounds of the Americanpopulation and distinguish between good and defective lineages.10

The Carnegie and Rockefeller institutions don’t give money to just anyone, but rather to fields ofresearch that their advisers judge promising. These advisers shared the generally favorable view ofeugenics that then prevailed among scientists and many intellectuals. The Eugenics ResearchAssociation included members from Harvard, Columbia, Yale and Johns Hopkins.11

“In America, the eugenic priesthood included much of the early leadership responsible for theextension of Mendelism,” writes the science historian Daniel Kevles. “Besides Davenport, therewere Raymond Pearl and Herbert S. Jennings, both of Johns Hopkins University; Clarence Little, thepresident of the University of Michigan and later the founder of the Jackson Laboratory in Maine; andthe Harvard professors Edward M. East and William E. Castle. . . . The large majority of Americancolleges and universities—including Harvard, Columbia, Cornell, Brown, Wisconsin, Northwestern,and Berkeley—offered well-attended courses in eugenics, or genetics courses that incorporatedeugenic material.” 12

The same conclusion is drawn by another historian of the eugenics movement, Edwin Black: “Theelite thinkers of American medicine, science and higher education were busy expanding the body ofeugenic knowledge and evangelizing its tenets,” he wrote. 13

Where so many eminent scientists led, others followed. Former president Theodore Rooseveltwrote to Davenport in 1913, “We have no business to permit the perpetuation of citizens of the wrongtype.” 14 The eugenics program reached a pinnacle of acceptance when it received the imprimatur ofthe U.S. Supreme Court. The court was considering an appeal by Carrie Buck, a woman whom theState of Virginia wished to sterilize on the grounds that she, her mother and her daughter were

mentally impaired.In the 1927 case, known as Buck v. Bell, the Supreme Court found for the state, with only one

dissent. Justice Oliver Wendell Holmes, writing for the majority, endorsed without reservation theeugenicists’ credo that the offspring of the mentally impaired were a menace to society.

“It is better for the world,” he wrote, “if instead of waiting to execute degenerate offspring forcrime, or to let them starve for their imbecility, society can prevent those who are manifestly unfitfrom continuing their kind. The principle that sustains compulsory vaccination is broad enough tocover cutting the Fallopian tubes. Three generations of imbeciles are enough.”

Eugenics, having started out as a politically impractical proposal for encouraging matches amongthe well-bred, had now become an accepted political movement with grim consequences for the poorand defenseless.

The first of these were sterilization programs. At the urging of Davenport and his disciples, statelegislatures passed programs for sterilizing the inmates of their prisons and mental asylums. Acommon criterion for sterilization was feeblemindedness, an ill-defined diagnostic category that wasoften identified by knowledge-based questions that put the ill educated at particular disadvantage.

Eugenicists perverted intelligence tests into a tool for degrading people. The tests had been firstdeveloped by Alfred Binet to recognize children in need of special educational help. The eugenicsmovement used them to designate people as feebleminded and hence fit for sterilization. Many of theearly tests probed knowledge, not native wit. Questions like “The Knight engine is used in the:Packard/Stearns/Lozier/Pierce Arrow” or “Becky Sharp appears in: Vanity Fair/Romola/AChristmas Carol/Henry IV” were heavily loaded against those who had not received a particular kindof education. As Kevles writes, “The tests were biased in favor of scholastic skills, and the outcomewas dependent upon the educational and cultural background of the person tested.” 15 Yet tests likethese were used to destroy people’s hopes of having children or deny them entry into military service.

Up until 1928, fewer than 9,000 people had been sterilized in the United States, even though theeugenicists estimated that up to 400,000 citizens were “feeble minded.” 16 After the Buck v. Belldecision, the floodgates opened. By 1930, 24 states had sterilization laws on their books, and by1940, 35,878 Americans had been sterilized or castrated.17

Eugenicists also began to influence the nation’s immigration laws. The 1924 Immigration Actpegged each country’s quota to the proportion of its nationals present in the 1890 census, a referencepoint later changed to the 1920 census. The intent and effect of the law was to increase immigrationfrom Nordic countries and restrict people from southern and eastern Europe, including Jews fleeingpersecution in Poland and Russia. In addition, the act barred all immigration from most East Asiancountries. As Congressman Robert Allen of West Virginia explained during the floor debate, “Theprimary reason for restriction of the alien stream . . . is the necessity for purifying and keeping purethe blood of America.” 18

The eugenicists had inspectors installed in the major capitals of Europe to screen prospectiveimmigrants. Almost a tenth were judged to be physically or mentally defective. The inspectoratecollapsed after a few years because of its expense, but its preferences lingered on in the minds ofU.S. consuls. When Jews in increasing numbers tried to flee Germany after 1936, U.S. consulsrefused to grant visas to them and other desperate refugees.19

Many supporters of the 1924 Immigration Act were influenced by a book called The Passing ofthe Great Race. Its author, Madison Grant, was a New York lawyer and conservationist who helped

found the Save the Redwoods League, the Bronx Zoo, Glacier National Park and Denali NationalPark. Despite his lack of scholarly credentials, Grant was powerful in anthropological circles andclashed frequently with Franz Boas, the founder of American social anthropology and a champion ofthe idea that significant differences between societies are cultural, not biological, in origin. Granttried to get Boas fired from his position as chair of the anthropology department at ColumbiaUniversity and fought a losing campaign with him over control of the American AnthropologicalAssociation.

Grant’s beliefs were starkly racist and eugenic. He considered that Europeans, based on the skulland other physical traits, consisted of three races, which he called Nordic, Alpine and Mediterranean.The Nordics, with their brown or blond hair and blue or pale eyes, were the superior type, in partbecause the harsh northern climate in which they evolved “must have been such as to impose a rigidelimination of defectives through the agency of hard winters and the necessity of industry andforesight in providing the year’s food, clothing and shelter during the short summer.”

It followed that “such demands on energy if long continued would produce a strong, virile andself-contained race which would inevitably overwhelm in battle nations whose weaker elements hadnot been purged.” 20

England’s decline was due to the “lowering proportion of its Nordic blood and the transfer ofpolitical power from the vigorous Nordic aristocracy and middle classes to the radical and laborelements, both largely recruited from the Mediterranean type,” Grant wrote. The “master race” wasthreatened by the same dilution in the United States: “Apparently America is doomed to receive inthese later days the least desirable classes and types from each European nation now exporting men.”

Emma Lazarus saw the United States as a beacon of hope for the refugees from Europe’s savagewars and hatreds. Grant had a less expansive vision to offer: “We Americans must realize that thealtruistic ideals which have controlled our social development during the past century and themaudlin sentimentalism that has made America ‘an asylum for the oppressed,’ are sweeping thenation toward a racial abyss. If the Melting Pot is allowed to boil without control and we continue tofollow our national motto and deliberately blind ourselves to all ‘distinctions of race, creed orcolor,’ the type of native American of Colonial descent will become as extinct as the Athenian of theage of Pericles, and the Viking of the days of Rollo.” 21

Grant’s book was little read by the 1930s, when Americans began to turn against eugenic ideas.But its shaping of the 1924 Immigration Act was not the least of its malignant effects. Grant receiveda fan letter one day from an ardent admirer who had incorporated many ideas from The Passing ofthe Great Race into a work of his own. “The book is my Bible,” the writer assured Grant. Grant’sfan, the author of Mein Kampf, was Adolf Hitler.22

The drift toward eugenics was not inexorable. In England, eugenic ideas never left the realm oftheory. The Galtonian version of eugenics at first attracted a wide following among the intelligentsia,including the playwright George Bernard Shaw and social radicals such as Beatrice and SidneyWebb. Winston Churchill, then home secretary, told eugenicists during discussion of the MentalDeficiency Act of 1913 that Britain’s 120,000 citizens deemed feebleminded “should, if possible, besegregated under proper conditions so that their curse died with them and was not transmitted tofuture generations.”

But Parliament did not favor sterilization. In 1931 and 1932 the Eugenics Society managed to getbills introduced to allow voluntary sterilization, but they went nowhere. There was no taste for such

extreme measures and, in any case, surgical sterilization of anyone, even with the person’s consent orthat of a court-appointed guardian, would have been considered a criminal act under English law.

The Eugenics Society in Britain had far less success in influencing public opinion thanDavenport’s eugenic lobby did in the United States. One reason was that most English scientists, afteran initial infatuation with Galton’s ideas, turned against eugenics, particularly the kind beingpromoted by Davenport.

Davenport believed that ill-defined traits such as “shiftlessness” or “feeblemindedness” werecaused by single genes and had the simple patterns of inheritance that Mendel had described in hisexperimental pea plants. But complex behavioral traits are generally governed by many genes actingin concert. While a Mendelian trait could in principle be almost eliminated by sterilizing its carriers,were it ethical to do so, complex traits are much harder to influence in this way.

A 1913 article by a member of the Galton laboratory, David Heron, attacked certain Americanwork for “careless presentation of data, inaccurate methods of analysis, irresponsible expression ofconclusions and rapid change of opinion.” Many recent contributions to the subject, in the writer’sview, threatened to place eugenics “entirely outside the pale of true science.” 23

The English critics were correct about the quality of Davenport’s science, although it continued tohold sway in the United States for many years more. When the Carnegie Institution got around toobtaining an objective review of Davenport’s work at the Eugenics Record Office in 1929, itsreviewers too found that the office’s data were worthless. A second review committee concluded in1935 that eugenics was not a science and that the Eugenics Record Office “should devote its entireenergies to pure research divorced from all forms of propaganda and the urging or sponsoring ofprograms for social reform or race betterment such as sterilization, birth control, inculcation of raceor national consciousness, restriction of immigration, etc.”

By 1933, eugenics had reached a fateful turning point. In both England and the United States,scientists had first embraced the idea and then turned against it, followed by their respective publics.Eugenics might have withered to a mere footnote in history if scientists in Germany had followedtheir colleagues in rejecting eugenic ideas. Hitler’s rise to power foreclosed any such possibility.

German eugenicists kept in close touch with their American colleagues both before and after theFirst World War. They saw that American eugenicists favored Nordic races and sought to keep thegene pool unsullied. They watched with keen interest as many state legislatures in the United Statesset up programs for sterilizing the mentally disabled, and as Congress changed the immigration lawsto favor immigrants from northern Europe over other regions of the world.

U.S. eugenic laws and ideology “became inspirational blueprints for Germany’s rising tide ofrace biologists and race-based hatemongers,” wrote the author Edwin Black.24 Hitler came to poweron January 30, 1933, and Germany’s eugenics program quickly got under way. In the Law for thePrevention of Defective Progeny, decreed on July 14, 1933, Germany identified nine categories ofpeople to be sterilized—the feebleminded and those with schizophrenia, manic depression,Huntington’s disease, epilepsy, deafness, hereditary deformities, hereditary blindness andalcoholism. The latter aside, these were the same illnesses targeted by Davenport and the Americaneugenicists.

Some 205 local Hereditary Health Courts were set up in Germany, each with three members—alawyer who served as chairman, a eugenicist and a physician. Doctors who failed to report suspectpatients were fined. Sterilizations began on January 1, 1934, and covered children over ten and

people at large, not just those in institutions. During the first year, 56,000 people were sterilized. By1937, the last year that records were published, the total had reached 200,000 people.

The purpose of the 1933 law, according to an official at the Reich Ministry of the Interior, was toprevent “poisoning the entire bloodstream of the race.” Sterilization would safeguard the purity of theblood in perpetuity. “We go beyond neighborly love; we extend it to future generations,” the officialsaid. “Therein lies the high ethical value and justification of the law.” 25

The sterilization program involved doctors and hospitals and created a legal and medical systemfor coercive treatment of those whom the National Socialists deemed unfit. With this machinery inplace, it was much easier to extend the eugenics program in two major directions. One was thetransition from sterilization to killing, prompted in part by the growing shortage of hospital beds asthe Second World War got under way. In 1939 some 70,000 mentally disabled patients in asylumswere designated for euthanasia. The first victims were shot. Later ones were forced into roomsdisguised as showers, where they were gassed.26

The other departure in Germany’s eugenics program was the addition of Jews to the list of thoseconsidered unfit. A succession of punitive laws drove Jews from their jobs and homes, isolated themfrom the rest of the population, and then confined those who had not already fled to concentrationcamps where they were murdered.

The first anti-Jewish decree, of April 7, 1933, provided for the dismissal of “non-Aryan” civilservants. The term “non-Aryan” offended foreign nations such as Japan. Future laws referred to Jewsexplicitly but plunged the Reich Ministry of the Interior into the problem of deciding who was a Jew.The National Socialist Party proposed that half-Jews be considered Jews, but the Ministry of theInterior rejected the idea as impractical. It divided half-Jews into two categories, considering them asfull Jews only if they belonged to the Jewish religion or were married to a Jew. Using this definition,the Nuremberg Law of September 13, 1935, otherwise known as the Law for the Protection ofGerman Blood and Honor, prohibited marriage between Jews and citizens of “German or relatedblood.” 27

These measures were followed by others that in a few years escalated to a program of massmurder of Jews in Germany and the European countries occupied by Hitler’s troops. Of the 9 millionJews who lived in Europe before the Holocaust, nearly 6 million were killed, including 1 millionchildren. The killing machine engulfed a further 4 to 5 million victims in the form of homosexuals,Gypsies and Russian prisoners of war. It was Hitler’s aim to depopulate the countries of EasternEurope so as to make room for German settlers.

Many of the elements in the National Socialists’ eugenics program could be found in theAmerican eugenics program, at least in concept, though not in degree. Nordic supremacy, purity of theblood, condemnation of intermarriage, sterilization of the unfit—all these were ideas embraced byAmerican eugenicists.

The destruction of the Jews, however, was Hitler’s idea. So too was the replacement ofsterilization with mass murder.

The fact that antecedents for the ideas that led to the Holocaust can be found in the American andEnglish eugenics movements of the 1920s and 1930s does not mean that others share responsibilityfor the crimes of the National Socialist regime. It does mean that ideas about race are dangerous whenlinked to political agendas. It puts responsibility on scientists to test rigorously the scientific ideasthat are placed before the public.

In Germany, scientists played a major role in paving the way for the destruction of the Jews butwere not solely culpable. Anti-Semitic statements mar the writings of leading German philosophers,including even Kant. Wagner ranted against the Jews in his operas and essays. “By the end of the FirstWorld War,” writes Yvonne Sherratt in her survey of intellectual influences on Hitler, “anti-Semiticideas pervaded every aspect of German thought from the Enlightenment to Romanticism, fromnationalism to science. Men of logic or the passions, Idealists or Social Darwinists, the highlysophisticated or the very crude, all supplied Hitler with the ideas to re-inforce and enact his dream.”28 Anti-Semitism was not an idea that German scientists found in science; rather, they found it in theirculture and allowed it to infect their science.

Scientia means “knowledge,” and true scientists are those who distinguish meticulously betweenwhat they know scientifically and what they don’t know or may only suspect. Those involved withDavenport’s eugenics program, including his sponsors at the Carnegie Institution and the RockefellerFoundation and their reviewers, failed to say immediately that Davenport’s ideas were scientificallydefective. Scientists’ silence or inattention allowed a climate of public opinion to develop in whichCongress could pass restrictive immigration laws, state legislatures could decree the sterilization ofthose judged mentally infirm and the U.S. Supreme Court could uphold unwarranted assaults on thecountry’s weakest citizens.

After the Second World War, scientists resolved for the best of reasons that genetics researchwould never again be allowed to fuel the racial fantasies of murderous despots. Now that newinformation about human races has been developed, the lessons of the past should not be forgotten andindeed are all the more relevant.

O

3

ORIGINS OF HUMAN SOCIALNATURE

Humankind’s behavioral unity exists, but it lies deeply buried under several thousand years of cumulativecultural evolution and is barely visible from the human realm.

—BERNARD CHAPAIS1

It deserves notice that, as soon as the progenitors of man became social . . . the principles of imitation, andreason, and experience would have increased, and much modified the instinctual powers in a way, of whichwe see only traces in the lower animals.

—CHARLES DARWIN2

ne of the strangest features of human anatomy, when people are compared with the other200 monkey and ape species in the primate family, is the sclera, or the white of the eye. Inall our primate cousins, the sclera is barely visible. In humans it stands out like a beacon,signaling to any observer the direction of a person’s gaze and hence what thoughts may be

on their mind.Why should such a feature have evolved? A signal that reveals a person’s thoughts to a

competitor or to an enemy on the battlefield can be a deadly handicap. For natural selection to havefavored it, there must be a compensating advantage of overwhelming magnitude. And that advantagemust have something to do with the social nature of the interaction, the abundant benefit conferred onall members of a group by being able to infer what others are thinking just by sizing up the directionof their gaze. The whites of the eyes are the mark of a highly social, highly cooperative species whosesuccess depends on the sharing of thoughts and intentions.

Human sociality is often assumed to be entirely a matter of culture, originating from the age of lifewhen children are taught to be nice to one another. A cascade of discoveries, many in the past decade,has made clear that this is not the case. Human sociality has been shaped by natural selection, just asmight be expected for any feature so crucial to survival. Sociality is written into our physical form, aswith the whites of the eyes and the self-mortifying phenomenon of blushing as a signal ofembarrassment. It is engraved in our neural circuitry too, most obviously in the faculty of language—there is no point in talking to oneself—and in many other behaviors. These include an inclination tofollow rules and an urge to punish others when they fail to do so. Shame and guilt are the penalties forour own failings. To achieve status and avert retribution, we are always seeking to burnish ourreputation. We trust the members of our in-group and are prepared to distrust the out-group. We often

know instinctively what is right and wrong.The genes that set up the circuitry of these social instincts have not yet been identified, but their

presence can be inferred from several lines of evidence that are described below. The salient fact isthat all types of human society, from the hunter-gatherer band to the modern nation, are rooted in asuite of social behaviors. These behaviors, which most probably have a genetic basis, interact withculture to produce the institutions that are characteristic of each society and help it survive in itsparticular environment.

Any trait that has a genetic basis can be changed by natural selection. The existence of genes thathave some bearing on human social behavior means that social behavior can be reworked byevolution and therefore can vary in time and place. But natural selection’s remodeling of humansocieties is far harder to identify than changes in skin color, say, because skin color dependsprimarily on the genes whereas social behavior, harder to measure in any case, is strongly influencedby culture.

Nonetheless, it is reasonable to assume that if traits like skin color have evolved in a population,the same may be true of its social behavior, and hence the very different kinds of society seen in thevarious races and in the world’s great civilizations differ not just because of their received culture—in other words, in what is learned from birth—but also because of variations in the social behavior oftheir members, carried down in their genes.

Given the vast power of culture to shape human social behavior, it’s necessary to look far back inevolutionary history to glimpse the signs of social behavior genes at work.

From Chimpanzee Society to Human Society

The nature of human society can most clearly be understood by tracing how it evolved. Humans andchimpanzees, our closest evolutionary cousins, split apart some 5 to 6 million years ago. There isreason to think that the joint ancestor of humans and chimps was far more chimplike than human.Chimpanzees seem to live in much the same habitat as they did 5 million years ago, and their basicway of life hasn’t changed. The apes at the head of the human lineage, on the other hand, abandonedthe forest and ventured out into the open savannahs of Africa, obliging them to go through manyevolutionary transitions in both body and behavior as they grew more and more unlike the jointancestor they shared with chimps.

If the joint ancestor of chimps and humans was chimplike, so too was its social behavior. Thesociety of living chimps can thus with reasonable accuracy stand in as a surrogate for the society ofthe joint ancestor and hence describe the baseline from which human social behavior evolved.

Chimp bands are hierarchical. An alpha male and one or two allies dominate the male hierarchy,and below that is a less visible female hierarchy. The males are fiercely territorial, probably toprotect the fruit trees that are the community’s chief source of food. Females usually stay and feed inone region of the territory. The larger each female’s region is and the more fruit trees it contains, themore children she can bear.

To maintain and increase the size of their territory, male chimps conduct regular patrols aroundits perimeter, with occasional forays into their neighbors’ territory. Male chimps are unremittinglyhostile to strange males and if possible will kill them on sight. Their favorite tactic on invadingenemy territory is to surprise and kill any male whom they find alone. If the raiding party senses that itis outnumbered, it will retreat. A neighboring territory will be captured after its resident males havebeen killed off one by one in a campaign that may last several years.

Chimp reproductive behavior requires a female to mate with all the males in her band, or at leastas many as possible. She is estimated to copulate between 400 and 3,000 times per conception. Thislabor provides an insurance policy for her children, since each male who thinks he might be the fatherof her child is more likely to refrain from killing it.

Despite the flamboyant promiscuity of female chimps, the alpha male somehow manages to fulfillhis droit du seigneur of fathering many of the community’s offspring—about 36% in one study basedon DNA paternity tests, or 45% excluding the close female relatives with whom he would avoidmating. The high-ranking males who were his allies together scored 50% of paternities.

An important feature of chimp communities is that the females mostly disperse to neighboringgroups when they reach adolescence, while the males stay in the community where they were born, anarrangement called patrilocality. Dispersal at puberty, which serves to avoid inbreeding, is commonin primate communities, except that most are matrilocal, meaning that it’s the males who disperse andthe females who stay in their home community. Chimps, many hunter-gatherer societies, and to someextent gorillas, are patrilocal. This arrangement probably has much to do with the chimp and humanpropensity for warfare: a group of males who have grown up together will be more cohesive indefending their own territory against rival groups. Since the males need to stay together, this obligesthe females to move so as to avoid inbreeding.

A strange feature of chimp society, at least from the human perspective, is that kinship is almost

invisible. If you are born into a chimp society, you will know your mother and the siblings born a fewyears before or after you, because these are the chimps who hang out around your mother. But youwill have no idea who your father is, though he must be one of the males in the community, nor anynotion of who his relatives are, even though you see them every day. You are equally ignorant of yourmother’s relatives, whom she left behind in her home community when she migrated to yours as ateenager. When a chimp raiding party enters neighboring territory, the males it kills may often berelatives or in-laws of the invaders’ daughters and sisters who dispersed there. But this kinship isunknown to the raiders.

How then was the profound transition made from the chimplike society of the joint ancestor to thehunter-gatherer societies in which all humans lived until 15,000 years ago and in which kinship was acentral institution? The likely steps in this process have been persuasively worked out by theprimatologist Bernard Chapais. The critical behavioral step, in his view, was formation of the pairbond, or at least a stable breeding relationship between male and female.

Consider a population of chimplike creatures living in a forest in Africa more than 5 millionyears ago. A fierce drought gripped Africa from 6.5 to 5 million years ago, and the forests shrank,giving way to open woodland or savannah. This was perhaps the event that forced the populationapart into two groups, one of which led to chimps and the other to humans. In response to the drought,some of the population clung to the traditional habitat and became the ancestors of chimps. Others leftthe trees and sought new sources of food on the ground, despite the risk of being caught in the open bylarge cats and other predators. This group became the ancestors of the human lineage.

The group trying life on the ground eventually started to walk upright, probably because walkingon two feet is more efficient than knuckle-walking, the great ape method of making the knuckles of thehands serve as a pair of forefeet. Freeing the hands, though an accidental by-product of walkingupright, was an adaptation of far-reaching significance because the hands could now be used forgripping tools and for gesturing.

Another adaptation, equally accidental and far-reaching, led to a transformation of socialstructure. This was the practice of mate guarding, which developed into the formation of stablebreeding relationships and eventually of the pair bond between one male and one female.

Males of almost all primate species, even chimps, guard females to some extent, so as to deterother males and improve their own chances of fathering the females’ children. Among the populationof chimplike ancestors that had left the trees, mate guarding would have become more common thanusual because of the more dangerous environment on the ground.

With the male often around for defense, he could also help in feeding and taking care of thechildren. Having at least two people involved in child rearing made an enormous difference, Chapaisargues. The period of juvenile dependence could last for several years longer. Children could beborn at an earlier stage in their development since they would be more protected, and earlier birthenabled the brain to do more of its growing outside the womb. The human brain eventually reachedthree times the size of that of chimps.

At first each male guarded as many females as he could, but another development drove themunwillingly toward monogamy. This was the emergence of weapons. At first, physical strength wasdecisive in fending off other males. But weapons are great equalizers because they tend to negate theadvantages of size. The cost of maintaining a large harem became too high for most males. Weaponsforced most to settle for one wife. The pair bond between male and female became established.

Having a dad around makes all the difference to social networks. In highly promiscuous societieslike those of chimps, an individual knows only its mother and the siblings it grows up with. With pairbonding, people know not only their father as well as their mother, but all their father’s relatives too.The males in a community now recognized both their daughters and, when their daughters dispersed toa neighboring group, a daughter’s husband and his parents.

The neighbors, who used to be treated as hostile, began now to be seen in an entirely differentlight. Those males, who once had to be killed on sight, were not the enemy—they were the in-laws,with an equal interest in promoting the welfare of one’s daughter’s or sister’s children. Thus in theincipient human line, a new and more complex social structure came into being, that of the tribe, agroup of bands bound to one another by exchange of women.

Warfare between neighboring bands, the chimp practice, was now pushed upward to the triballevel. Tribes would fight as savagely as before, but among the bands within each tribe cooperationwas now the rule.

This profound transition in social structure started some time after the split of the ancestralpopulations leading to chimps and humans. Pair bonding, an essential element of the new socialstructure, probably did not become significant until the emergence of Homo ergaster some 1.7million years ago. This is the first human ancestor in which the males were not very much larger thanthe females. A large size difference between the sexes, as in gorillas, indicates competition betweenmales and a harem structure. The size difference diminishes as pair bonding becomes more common.

Given the distinctiveness of chimp social behavior, there is no reason to doubt that it has agenetic basis. Both the chimp and human lineages would have inherited a suite of genes governingsocial behavior and in each species the genes for social behavior would have evolved as socialstructure changed in response to the society’s requirements for survival.

Chimp social structure, in fact, may not differ much from that of the joint chimp-human ancestor.But human social structure has changed profoundly over the past 5 million years. Just as physicalform was changing from ape to human, social behavior was undergoing a radical transformation fromthe chimplike behavior of multimale bands to the human pair-bond system. There is every reason tosuppose that the development of distinctive social behavior in humans had a genetic basis, just assurely as the physical changes did. And if social behavior was under genetic control during theevolution of human society from that of a chimplike ancestor, it is hard to see why it should not havecontinued to be molded by evolutionary forces up until the present day.

Social behavior changes in response to changes in the environment. As the hominid groupsabandoned the trees, for eons the primates’ safe refuge, their societies had to adapt to the richeropportunities and more serious perils of life on the ground. This highly risky endeavor required athorough makeover of standard ape social behavior, most pertinently in the degree of cooperationbetween individuals.

The Distinctive Human Virtue: Cooperation

Chimps will cooperate in certain ways, like assembling in war parties to patrol the borders of theirterritory. But beyond the minimum requirements for being a social species, they have little instinct tohelp one another. Chimps in the wild forage for themselves. Even chimp mothers regularly decline toshare food with their children, who are able from a young age to gather their own food. When themothers do share food, it’s always the rind or husk or less desirable part that is given to the child.3

In the laboratory, chimps don’t naturally share food either. With some exceptions, mostexperiments show chimps to be severely lacking in altruistic sentiments for other chimps. If a chimpis put in a cage where he can pull in one tray of food for himself or, with no greater effort, a tray thatalso provides food for a neighbor in the next cage, he will pull indiscriminately—he just doesn’t carewhether his neighbor gets fed or not. Yet he’s perfectly aware that one of the trays carries a portion offood made available to the neighboring cage. If the cage next door is empty and the chimp is allowedaccess to it, he will usually pull the tray with the double portion. Chimps are truly selfish.4

Human children, on the other hand, are inherently cooperative. From the earliest ages, they desireto help others, to share information and to participate in pursuing common goals. The developmentalpsychologist Michael Tomasello has studied this cooperativeness in a series of experiments withvery young children. He finds that if infants aged 18 months see an unrelated adult with hands fulltrying to open a door, almost all will immediately try to help. If the adult pretends to have lost anobject, children from as young as 12 months will helpfully point out where it is.

There are several reasons to believe that the urges to help, inform and share are “naturallyemerging” in young children, Tomasello writes, meaning that they are innate, not taught.5 One is thatthese instincts appear at a very young age before most parents have started to train their children tobehave socially. Another is that the helping behaviors are not enhanced if the children are rewarded.

A third reason is that social intelligence develops in children before their general cognitiveskills, at least when compared with apes. Tomasello gave human and chimp children a battery of testsrelated to understanding the physical and social worlds. The human children, aged 2.5 years, did nobetter than the chimps on the physical world tests but were considerably better at understanding thesocial world.6

The essence of what children’s minds have and chimps’ don’t is what Tomasello calls sharedintentionality. Part of this ability is that they can infer what others know or are thinking, a skill calledtheory of mind. But beyond that, even very young children want to be part of a shared purpose. Theyactively seek to be part of a “we,” a group that has pooled its talents and intends to work toward ashared goal.

Children of course have the selfish motivations necessary for survival, like any other animal, buta vigorous social instinct is overlaid on their behavior from a very young age. The social instinct getsmodulated in later life as the children learn to make distinctions about whom they can trust and whodoes not reciprocate.

Besides shared intentionality, another striking social behavior is that of following norms, or rulesgenerally agreed on within the “we” group. Allied with the rule following are two other basicprinciples of human social behavior. One is a tendency to criticize, and if necessary punish, thosewho do not follow the agreed-upon norms. Another is to bolster one’s own reputation, presenting

oneself as an unselfish and valuable follower of the group’s norms, an exercise that may involvefinding fault with others.

The first two behaviors are already evident in very young children. Tomasello showed a group oftwo- and three-year-olds a new game. A puppet then appeared and performed the game incorrectly.Almost all the children protested the puppet’s actions and many explicitly objected, telling the puppethow the game should be played. “Social norms—even of this relatively trivial type—can only becreated by creatures who engage in shared intentionality and collective beliefs,” Tomasello writes,“and they play an enormously important role in maintaining the shared values of human culturalgroups.” 7

The urge to punish deviations from social norms is a distinctive feature of human societies. Inprinciple it carries great risks for the punisher. In tribal or hunter-gatherer societies, anyone whopunishes a miscreant is likely to have vengeance wreaked upon him by the miscreant’s family. Sopunishment in practice is meted out fairly deliberately. First, through social gossip, a consensus isarrived at that an individual’s behavior merits correction. Punishment may then be carried outcollectively, by shunning or even ostracizing the deviant member. A different problem arises whenthe offender refuses to reform and must be killed. Hunter-gatherers will usually persuade his family todo the job because anyone else will bring down a blood feud on his head.

Social norms and punishment of deviants are behaviors embedded so deeply in the human psychethat special mechanisms have arisen for punishing oneself for infractions of social norms: shame andguilt, which are sometimes physically expressed by blushing.

A delicate balance was being maintained during the evolution of human social structure. Ashuman brain size increased, individuals could calculate to an ever greater degree where their ownself-interest lay and how it might be served at the group’s expense. To deter freeloading, ever moresophisticated countermechanisms were required. Together with shame and guilt, an inbuilt sense ofmorality evolved, one that gave people an instinctive aversion to murder and other crimes, at leastagainst members of their own group. A propensity for religious behavior bound people together inemotion-laden rituals that affirmed commitment to common goals. And religion instituted a vigilantoverseer of people’s actions, a divine avenger who would punish infractions with disaster in thisworld and torment in the next.

As these mechanisms for group cohesion evolved, humans became the most social of animals, andtheir societies, growing ever more capable, began the series of achievements that was to leadeventually to the first settlements and agriculture.

The Hormone of Social Trust

Human sociability is two-edged. The trust extended to members of one’s own group is mirrored bythe suspicion and potential mistrust shown toward strangers. Willingness to defend one’s own peopleis the counterpart of readiness to kill the enemy. Human morality is not universal, as philosophershave argued: it is strictly local, at least in its instinctual form. Reflections of this ambivalence arenow apparent from the level of the genes.

If human social nature is innate and has evolved, as seems highly likely, there will be evidence ofits evolution in the genome. Very little about the genes that govern the human brain is yet understood,so it need be no surprise that not much is yet known about the genetic basis of human social behavior.A prominent exception concerns the neural hormone called oxytocin, sometimes known as thehormone of trust. It is synthesized in a region in the base of the brain known as the hypothalamus andfrom there is distributed to both brain and body, with separate roles in each. In the body, oxytocin isreleased when a woman gives birth and when she gives milk to her child.

In the brain, oxytocin has a range of subtle effects that are only beginning to be explored. Ingeneral, it seems that oxytocin has been co-opted in the course of evolution to play a central role insocial cohesion. It’s a hormone of affiliation. It dampens down the distrust usually felt towardstrangers and promotes feelings of solidarity. “It increases men’s trust, generosity and willingness tocooperate,” say the authors of a recent review.8 (The same is doubtless true of women too but mostsuch experiments are performed only in men because of the risk that oxytocin might make a womanmiscarry if she were unknowingly pregnant.)

The trust promoted by oxytocin is not of the brotherhood of man variety—it’s strictly local.Oxytocin engenders trust toward members of the in-group, together with feelings of defensivenesstoward outsiders. This limitation in oxytocin’s radius of trust was discovered only recently byCarsten De Dreu, a Dutch psychologist who doubted the conventional wisdom that oxytocin simplypromoted general feelings of trust. Any individual who blindly trusts everyone is not going to prosperin the struggle for survival, De Dreu supposed, and his genes would be rapidly eliminated; hence itseemed much more likely that oxytocin promoted trust only in certain contexts.

De Dreu showed in several ingenious experiments that this is indeed the case. In one, the youngDutch men who were his subjects were presented with standard moral dilemmas, such as whether tosave five people in the path of a train for the loss of one life, that of a bystander who could be thrownonto the tracks to stop the train. The people to be saved were all Dutch but the person to be killedwas sometimes given a Dutch first name, like Pieter, and sometimes a German or Muslim name, likeHelmut or Muhammad. (Opinion polls show that neither is a favorite nationality among the Dutch.)

When the subjects had taken a sniff of oxytocin, they were much more inclined to sacrifice theHelmuts and the Muhammads, De Dreu found, showing the dark side of oxytocin in making peoplemore willing to punish outsiders. Oxytocin does not seem to promote positive aggression towardoutsiders, he finds, but rather it heightens the willingness to defend the in-group.9

The two-edged nature of oxytocin is just what might be expected to suit the needs of ancestralhumans living in small tribal groups where every stranger was a possible enemy. In larger societies,for instance in cities, where people must often do business with strangers, the general level of trustneeds to be considerably higher than in tribal societies, where most interactions are with close kin.

So deep are oxytocin’s roots that it is involved in the most basic aspect of human sociality, that ofrecognizing people’s faces. Doses of oxytocin improve a subject’s recognition of human faces.Genetic variations in the gene that specifies the oxytocin receptor protein are associated withimpaired face recognition.10

When oxytocin reaches a target neuron, it interacts with a receptor protein that juts out from theneuron’s surface and is crafted to recognize oxytocin specifically. The strength with which thesereceptors bind to oxytocin can be varied by making small changes in the receptor’s gene. Anexperiment to test this of course cannot be done in people, but relevant evidence comes fromcomparing two species of vole. Male prairie voles are monogamous and make caring, trustworthyfathers, whereas male meadow voles are roaming polygamists who leave much to be desired in thefatherhood realm. If meadow voles are genetically engineered so as to stud their neurons with extrareceptors for vasopressin, a hormone very similar to oxytocin, these Lotharios suddenly becomemonogamous.11

It’s easy to see how natural selection could increase the general degree of trust in humansocieties, whether by raising the brain’s production of oxytocin, by inserting more oxytocin receptorsinto people’s neurons, or by enhancing the tenacity with which the receptors hold on to oxytocin. Theopposite processes would lower the degree of social trust. It is not yet known by what specificmechanism the oxytocin levels in people are controlled. But the oxytocin mechanism can evidently bemodulated by natural selection so as to achieve either more or less of the same effect. If an inclinationto distrust others should favor survival, people with lower oxytocin levels will flourish and havemore children, and in several generations, a society will become less trusting. Conversely, if strongerbonds of trust help a society flourish, genes that increase oxytocin levels will become more common.

This is not to imply that trust in human societies is set exclusively by the genes. Culture is farmore important in most short-term interactions. As with most human behaviors, the genes provide justa nudge in a certain direction. But these small nudges, acting on every individual, can alter the natureof a society. Small changes in social behavior can, in the long term, deeply modify the social fabricand make one society differ significantly from another.

Control of Aggression

Besides trust, another important social behavior that is clearly under genetic influence is that ofaggression, or rather the whole spectrum of behaviors that runs from aggression to shyness. The factthat animals can be domesticated is proof that the trait can be modulated by the selective pressures ofevolution.

One of the most dramatic experiments on the genetic control of aggression was performed by theSoviet scientist Dmitriy Belyaev. From the same population of Siberian gray rats he developed twostrains, one highly sociable and the other brimming with aggression. For the tame rats, the parents ofeach generation were chosen simply by the criterion of how well they tolerated human presence. Forthe ferocious rats, the criterion was how adversely they reacted to people. After many generations ofbreeding, the first strain was now so tame that when visitors entered the room where the rats werecaged, the animals would press their snouts through the bars to be petted. The other strain could nothave been more different. The rats would hurl themselves screaming toward the intruder, thuddingferociously against the bars of their cage.12

Rodents and humans use many of the same genes and brain regions to control aggression.Experiments with mice have shown that a large number of genes are involved in the trait, and thesame is certainly true of people. Comparisons of identical twins raised together and separately showthat aggression is heritable. Genes account for between 37% and 72% of the heritability, the variationof the trait in a population, according to various studies. But very few of the genes that underlieaggression have yet been identified, in part because when many genes control a behavior, each has sosmall an effect that it is hard to detect. Most research has focused on genes that promote aggressionrather than those at the other end of the behavioral spectrum.

One of the genes associated with aggression is called MAO-A, meaning that it makes one of twoforms of an enzyme called monoamine oxidase. The enzyme has a central role in maintaining normalmental states through its cleanup function—it breaks down three of the small neurotransmitterchemicals used to convey signals from one neuron to another. The three neurotransmitters, serotonin,norepinephrine, and dopamine, need to be disposed of after accomplishing their signaling task. Ifallowed to accumulate in the brain, they will keep neurons activated that should have returned to rest.

The role of MAO-A in the control of aggression came to light in 1993 through the study of a Dutchfamily in which the men were inclined to violently deviant behavior, such as impulsive aggression,arson, attempted rape and exhibitionism. The eight affected men had inherited an unusual form of theMAO-A gene. A single mutation in the gene causes the cell’s assembly of the MAO-A enzyme to behalted halfway through, rendering it ineffective. In the absence of functioning MAO-A enzymes,neurotransmitters build up in excess, causing the men to be overaggressive in social situations.13

Mutations that totally disrupt a gene like MAO-A have serious consequences for the individual.There are more subtle ways in which a gene like MAO-A can be modulated by natural selection so asto make people either more or less aggressive. Genes are controlled by elements called promoters,which are short stretches of DNA that lie near the genes they control. And being made of DNA, thepromoters can incur mutations just like the DNA of the genes.

As it happens, the promoter for MAO-A is quite variable in the human population. People mayhave two, three, four or five copies of it, and the more copies they have, the more of the MAO-A

enzyme their cells produce. What difference does this make to a person’s behavior? Quite a lot, itturns out. People with three, four or five copies of the MAO-A promoter are normal but those withonly two copies have a much higher level of delinquency. From a questionnaire given to 2,524 youthsin the United States, Jean Shih and colleagues found that men with just two promoters weresignificantly more likely to report that they had committed both serious delinquency within theprevious 12 months, such as theft, selling drugs or damaging property, and violent assaults, such ashurting someone badly enough to need medical care or threatening someone with a knife or gun.Women with two promoters also reported much higher levels of serious and violent delinquency thanthose with more promoters.14

If individuals can differ in the genetic structure of their MAO-A gene and its controls, is the samealso true of races and ethnicities? The answer is yes. A team led by Karl Skorecki of the RambamHealth Care Center in Haifa looked at variations in the MAO-A gene in people from seven ethnicities—Ashkenazi Jews, Bedouins, African pygmies, aboriginal Taiwanese, East Asians (Chinese andJapanese), Mexicans and Russians. They found 41 variations in the portions of the gene they decoded,and the pattern of variation differed from one ethnicity to the next, revealing a “substantialdifferentiation between populations.”

The pattern of variation could have arisen from random mutations in the DNA that had no effecton the MAO-A enzyme or on people’s behavior. But after applying various tests, the researchersconcluded there was possible evidence for “positive selection, potentially acting on MAO-A-relatedphenotypes.” 15 This means they think that natural selection could have favored particular behavioraltraits in the various ethnicities, whether more or less aggressive, and that this could have caused theparticular patterns of variation in the MAO-A gene. But the researchers did not examine the behaviorsof the various ethnicities so could not establish causal links between each pattern of variations in theMAO-A enzyme and specific behavioral traits.

Such a link has been asserted by a research team led by Michael Vaughn of Saint LouisUniversity. He and his colleagues looked at the MAO-A promoters in African Americans. Thesubjects were the same 2,524 American youths in the study by Shih mentioned above. Of the AfricanAmerican men in the sample, 5% carried two MAO-A promoters, the condition that Shih had found tobe associated with higher levels of delinquency. Members of the two-promoter group weresignificantly more likely to have been arrested and imprisoned than African Americans who carriedthree or four promoters. The same comparison could not be made in white, or Caucasian, males, theresearchers report, because only 0.1% carry the two-promoter allele.16

A finding like this has to be interpreted with care. First, like any scientific report, it needs to berepeated by an independent laboratory to be sure it is valid. Second, a large number of genes areevidently involved in controlling aggression, so even if African Americans are more likely to carrythe violence-linked allele of MAO-A promoters than are Caucasians, Caucasians may carry theaggressive allele of other genes yet to be identified. Indeed a variant of a gene called HTR2B, anallele that predisposes carriers to impulsive and violent crimes when under the influence of alcohol,has been found in Finns.17 It is therefore impossible, by looking at single genes, to say on geneticgrounds that one race is genetically more prone to violence than any other. Third, genes don’tdetermine human behavior; they merely create a propensity to behave in a certain way. Whether apropensity to violence is exercised depends on circumstances as well as genetic endowment, so thatpeople who live in conditions of poverty and unemployment may have more inducements to violence

than those who are better off.The wider point illustrated by the case of the MAO-A gene is that important aspects of human

social behavior are shaped by the genes and that these behavior traits are likely to vary from one raceto another, sometimes significantly so.

How Societies Change to Fit Environment

Trust and aggression are two significant components of human social behavior whose underlyinggenetics have already been to some extent explored. There are many other aspects of social behavior,such as conformity to rules, the willingness to punish violators of social norms or the expectation offairness and reciprocity, that most probably have a genetic basis, although one that remains to bediscovered.

The fact that human social behavior is to some extent shaped by the genes means that it can evolveand that different kinds of society can emerge as the underlying social behaviors shift. Conversely,major changes in human society, such as the transition from hunter-gathering to settled life, werealmost certainly accompanied by evolutionary changes in social behavior as people adapted to theirnew way of life. (The words adapt and adaptation are always used here in the biological sense of agenetically based evolutionary response to circumstances.)

There are two important factors to consider in the emergence of social change. One is that asociety develops through changes in its institutions, which are blends of culture and geneticallyshaped social behavior. The other is that the genes and culture interact. This may seem paradoxical toanyone who considers genes and culture to be entirely separate realms. But it is scarcely surprisingfrom an evolutionary perspective, given that the genome is designed to respond to the environment,and a major component of the human environment is society and its cultural practices.

The working components of a society are its institutions. Any socially agreed-upon form ofbehavior, from a tribal dance to a parliament, may be considered an institution. Institutions reflectboth culture and history, but their basic building blocks are human behaviors. Follow an institution allthe way down, and beneath thick layers of culture, it is built on instinctual human behaviors. The ruleof law would not exist if people didn’t have innate tendencies to follow norms and to punishviolators. Soldiers could not be made to follow orders were not army discipline able to invoke innatebehaviors of conformity, obedience and willingness to kill for one’s own group.

So consider the intricate dynamics of the natural system in which the members of a human societyare embedded. Their basic motivation is their own survival and that of their families. Unlike speciesthat can only interact directly with their environment, people often do so through their society and itsinstitutions. In responding to an environmental change, a society adjusts its institutions, and itsmembers adjust to the new institutions by changing their culture in the short term and their socialbehavior in the long term.

The idea that human behavior has a genetic basis has long been resisted by those who see themind as a blank slate on which only culture can write. The blank slate notion has been particularlyattractive to Marxists, who wish government to mold socialist man in its desired image and who seegenetics as an impediment to the power of the state. Marxist academics led the attack on Edward O.Wilson when he proposed in his 1975 book Sociobiology that social behaviors such as conformityand morality had a genetic basis. Wilson even suggested that genes might have some influence “in thebehavioral qualities that underlie variations between cultures.” 18 Although his term sociobiology isnot now widely used—evolutionary psychology is a less controversial term for much the same thing—the tide has turned in favor of Wilson’s ideas now that many human faculties seem to be innate.From the social repertoire of babies to the moral instincts discernible from psychological tests, it is

clear that the human mind is hereditarily predisposed to act in certain ways.Social behavior changes because, over a period of generations, genes and culture interact. “The

genes hold culture on a leash,” Wilson writes. “The leash is very long but inevitably values will beconstrained in accordance with their effects on the human gene pool.” 19 Harmful cultural practicesmay lead to extinction, but advantageous ones create selective pressures that can promote specificgenetic variants. If a cultural practice provides a significant survival advantage, genes that enable aperson to engage in that practice will become more common.

This interaction between the genome and society, known as gene-culture evolution, has probablybeen a powerful force in shaping human societies. At present it has been documented for only minordietary changes, but these establish the principle. The leading example is that of lactose tolerance, theability to digest milk in adulthood by means of the enzyme lactase, which breaks down lactose, theprincipal sugar in milk.

Figure 3.1. Distribution of lactose tolerance in present-day Europe (dark gray = 100%). Dotted area showshomeland of Funnel Beaker Culture, which flourished 6,000 to 5,000 years ago.

SOURCE: ALBANO BEJA-PEREIRA, NATURE GENETICS 35 (2003), PP. 311–15

In most human populations, the lactase gene is permanently switched off after weaning so as tosave the energy required to make the lactase enzyme. Lactose, the sugar metabolized by the lactaseenzyme, occurs only in milk, so that when a person has finished breast-feeding, lactase will never beneeded again. But in populations that learned to herd cattle and drink raw cow’s milk, notably theFunnel Beaker Culture that flourished in north central Europe from 6,000 to 5,000 years ago, there

was a great selective advantage in keeping the lactase gene switched on. Almost all Dutch andSwedish people today are lactose tolerant, meaning they carry the mutation that keeps the lactase genepermanently switched on. The mutation is progressively less common in Europe with increasingdistance from the core region of the ancient Funnel Beaker Culture.

Three different mutations that have the same result have been detected in pastoral peoples ofeastern Africa. Natural selection has to work on whatever mutations are available in a population,and evidently different mutations were available in the European and various African peoples whotook up cattle raising and drinking raw milk. The lactase-prolonging mutations conferred an enormousadvantage on their owners, letting them leave ten times more surviving children than those without themutation.20

Lactose tolerance is a fascinating example of how a human cultural practice, in this case cattleraising and drinking raw milk, can feed back into the human genome. The genes that underlie socialbehavior have for the most part not yet been identified, but it’s a reasonable assumption that they toowould have changed in response to new social institutions. In larger societies requiring a higherdegree of trust, people who trusted only their close kin would have been at a disadvantage. Peoplewho were more trusting would have had more surviving children, and any genetic variation thatpromoted this behavior would become more common in each successive generation.

The Shaping of Human Social Behavior

Changes in the social behaviors that underlie a society’s institutions take many generations toaccomplish. It may have been in hunting or scavenging that early humans first faced strong selectivepressure to cooperate. Hunting is much more efficient when done as a group; indeed that’s the onlyway that large game can be taken down, butchered and guarded from rivals. Hunting may haveinduced the shared intentionality that is characteristic of humans; groups that failed to cooperateclosely did not survive. Along with cooperativeness emerged the rules for sharing meat in anequitable way and the gossip machinery that punished bragging and stinginess.

A hunter-gatherer society consists of small, egalitarian bands without leaders or headmen. Thiswas the standard human social structure until 15,000 years ago. That it took 185,000 years for peopleto take the seemingly obvious step of settling down and putting a permanent roof over their headsstrongly suggests that several genetic changes in social behavior had to evolve first. The aggressiveand independent nature of hunter-gatherers, accustomed to trusting only their close kin, had to yield toa more sociable temperament and the ability to interact peaceably with larger numbers of people. Aforaging society that turns to agriculture must develop a whole new set of institutions to coordinatepeople in the unaccustomed labor of sowing and harvesting crops.

In this novel environment, people skilled in farming and in operating in larger communitiesprospered and left more children; those whose only skill was in hunting did less well and placedfewer of their children and genes in the next generation. In time, the nature of the society and itsmembers changed as its institutions were transformed to serve the new way of life.

After the first settlements, a wave of new societies then came into being in response to populationpressure and new ways of gathering food. The anthropologist Hillard Kaplan and colleagues haveworked out the dynamics of several of these adaptations.21

One reason why hunter-gatherer societies are egalitarian is that their usual food sources—gameanimals, tubers, fruits and nuts—tend to be dispersed and are not easily monopolized. In tribalhorticulture, as practiced in New Guinea and parts of South America, people live in settled villageswith gardens that must be planted and defended. This mode of life requires more structure than ahunter-gatherer band. People accept the governance of a headman to organize defense and conductdiplomatic relations with neighboring groups.

Tribal pastoralism creates an even greater demand for military leadership because the tribe’schief resource, herds of cattle or sheep, can easily be captured and driven off. Competition forgrassland is another source of friction. Pastoralists have developed the necessary institutions forfrequent warfare, which often include the social segregation of young warrior classes andexpansionary male lineages.

The rise of the first city-states, based on large scale agriculture, required a new kind of socialstructure, one based on large, hierarchically organized populations ruled by military leaders. Thestates overlaid their own institutions on those of the tribe. They used religion to legitimate the ruler’spower and maintain a monopoly of force.

The common theme of all these developments is that when circumstances change, when a newresource can be exploited or a new enemy appears on the border, a society will change its institutionsin response. Thus it’s easy to see the dynamics of how human social change takes place and why such

a variety of human social structures exists. As soon as the mode of subsistence changes, a society willdevelop new institutions to exploit its environment more effectively. The individuals whose socialbehavior is better attuned to such institutions will prosper and leave more children, and the geneticvariations that underlie such a behavior will become more common. If the pace of warfare increases,a special set of institutions will emerge so as to increase the society’s military preparedness. Thesenew institutions will feed back into the genome over the course of generations, as those with thesocial behaviors that are successful in a militaristic society leave more surviving children.

This process of continuous adaptation has taken a different course in each region of the worldbecause each differed in its environment and exploitable resources. As population increased,coordinating the activities of larger numbers of people required more complex social structures.Tribes merged into archaic states, states became empires, and empires rose and fell, leaving behindthe large scale structures known as civilizations.

The process of organizing people in larger and larger social structures, with accompanyingchanges in social behavior, has most probably been molded by evolution, though the underlyinggenetic changes have yet to be identified. This social evolution has proceeded roughly in parallel inthe world’s principal populations or races, those of Africans, East Asians and Caucasians.(Caucasian includes Europeans, the peoples of the Indian subcontinent and Middle Easterners.) Thesame process is visible in a fourth race, the natives of North and South America. Because theAmericas were populated much later than Africa and Eurasia—the first settlers crossed the BeringStrait from Siberia only 15,000 years ago—social evolution got a much later start and the greatempires of the Incas and Mayans emerged several thousand years later than their counterparts inEurasia. In a fifth race, the peoples of Australia and Papua New Guinea, population numbers werealways too low to ignite the processes of settlement and state building.

How Evolution Creates Different Societies

People are entirely different from ants, yet there is something to be learned from the creatures thatoccupy the other pinnacle of social evolution in nature. An ant is an ant is an ant, yet natural selectionhas crafted a profusion of widely different ant societies, each adapted to its own ecological niche.Leaf-cutter ants are superb agriculturalists, tending underground gardens of a mushroomlike funguswhich they protect with special antibiotics. There are ants that live in the hollow thorns provided forthem by acacia trees. Some ants specialize in preying on termite nests. Weaver ants sew leavestogether to construct shelters for their colonies. Army ants kill every living thing that cannot escapefrom their intense raiding parties.

In the case of ants, evolution has generated their many different kinds of society by keeping the antbody much the same and altering principally the behavior of each society’s members. People too livein many different types of society, and evolution seems to have constructed these with the samestrategy—keep the human body much the same but change the social behavior.

A principal difference is that people, with their far greater intelligence, construct societies full ofcomplex interactions in which an individual with stereotyped behavior like an ant’s would be at asevere disadvantage. Learned behavior, or culture, plays a dominant role in human societies, shapedby a small, though critical, set of genetically influenced social behaviors. In ant societies, by contrast,social behavior is dominated by the genes and the genetically prescribed pheromones that govern themajor activities of an ant society.

In human societies, individuals’ behavior is therefore flexible and generalist, with much of asociety’s specificity being embedded in its culture. Human societies are not nearly as diverse as thoseof ants because evolution has had a mere 50,000 years in which to shape modern human populations,compared with the 100 million years of ant evolution.

Another major difference is that among people, individuals can generally move easily from onesociety to another. Ants will kill ants from other species or even a neighboring colony of the samespecies. Apart from slavery—some species of ant will enslave other species—ant societies areimmiscible. The institutions of ant societies are shaped almost entirely by genetics and little, if at all,by culture. There is no way that army ants can be trained to stop raiding and turn to peacefulhorticulture like leaf-cutter ants. With human societies, institutions are largely cultural and based on amuch smaller genetic component.

In the case of both ants and people, societies evolve over time as natural selection modifies thesocial behavior of their members. With ants, evolution has had time to generate thousands of differentspecies, each with a society adapted to survival in its particular environment. With people, who haveonly recently dispersed from their ancestral homeland, evolution has so far generated only raceswithin a single species, but with several major forms of society, each a response to differentenvironments and historical circumstances. New evidence from the human genome now makes itpossible for the first time to examine this differentiation of the human population at the genetic level.

T

4

THE HUMAN EXPERIMENT

There is, however, no doubt that the various races, when carefully compared and measured, differ much fromeach other. . . . The races differ also in constitution, in acclimatisation and in liability to certain diseases. Theirmental characteristics are likewise very distinct; chiefly as it would appear in their emotional, but partly intheir intellectual faculties.

—CHARLES DARWIN1

hrough independent but largely parallel evolution among the populations of each continent,the human species has differentiated into races. This evolutionary process is hard toexplore, however, when the question of race is placed under taboo or its existence isdenied outright.

Many scholars like to make safe nods to multicultural orthodoxy by implying that human races donot exist. Race? Debunking a Scientific Myth is the title of a recent book by a physicalanthropologist and a geneticist, though their text is not nearly so specific.2 “The concept of race hasno genetic or scientific basis,” writes Craig Venter, who was the leading decoder of the humangenome but has no known expertise in the relevant discipline of population genetics.3

Only people capable of thinking the Earth is flat believe in the existence of human races,according to the geographer Jared Diamond. “The reality of human races is another commonsense‘truth’ destined to follow the flat Earth into oblivion,” he asserts.4 For a subtler position, consider thefollowing statement, which seems to say the same thing. “It is increasingly clear that there is noscientific basis for defining precise ethnic or racial boundaries,” writes Francis Collins, director ofthe National Human Genome Research Institute in a review of the project’s implications.5 This formof words, commonly used by biologists to imply that they accept the orthodox political take on thenonexistence of race, means rather less than meets the eye. When a distinct boundary developsbetween races, they are no longer races but separate species. So to say there are no preciseboundaries between races is like saying there are no square circles.

A few biologists have begun to agree that there are human races, but they hasten to add that thefact means very little. Races exist, but the implications are “not much,” says the evolutionarybiologist Jerry Coyne.6 Too bad—nature has performed this grand 50,000 year experiment, generatingscores of fascinating variations on the human theme, only to have evolutionary biologists expressdisappointment at her efforts.

From biologists’ obfuscations on the subject of race, sociologists have incorrectly inferred thatthere is no biological basis for race, confirming their preference for regarding race as just a social

construct. How did the academic world contrive to reach a position on race so far removed fromreality and commonsense observation?

The politically driven distortion of scientific views about race can be traced to a sustainedcampaign from the 1950s onward by the anthropologist Ashley Montagu, who sought to make theword race taboo, at least when referring to people. Montagu, who was Jewish, grew up in the EastEnd district of London, where he experienced considerable anti-Semitism. He was trained as a socialanthropologist in London and New York, where he studied under Franz Boas, a champion of racialequality and the belief that culture alone shapes human behavior. He began to promote Boas’s ideaswith more zeal than their author. Montagu developed passionate views on the evils of race. “Race isthe witchcraft, the demonology of our time, the means by which we exorcise the imagined demoniacalpowers among us,” he wrote. “It is the contemporary myth, humankind’s most dangerous myth,America’s Original Sin.” 7

In the postwar years, with the horror of the Holocaust weighing on people’s minds, Montagufound ready acceptance of his views. These were prominent in the influential UNESCO statement onrace, first issued in 1950, which he helped draft. He believed that imperialism, racism and anti-Semitism were driven by notions of race and could be undermined by showing that races did notexist. However much one may sympathize with Montagu’s motives, it is perhaps simplistic to believethat an evil can be eliminated by banning the words that conceptualize it. But suppression of the wordwas Montagu’s goal, and to a remarkable extent he succeeded.

“The very word race is itself racist,” he wrote in his book Man’s Most Dangerous Myth: TheFallacy of Race. 8 Many scholars who understood human races very well began to drop the use of theterm rather than risk being ostracized as racists. In a survey taken in 1987, only 50% of physicalanthropologists (researchers who deal with human bones) agreed that human races exist, and amongsocial anthropologists (who deal with people) just 29% did so.

The physical anthropologists best acquainted with race are those who do forensics. Human skullsfall into three distinctive shapes, which reflect their owners’ degree of ancestry in the three mainraces, Caucasian, East Asian and African. African skulls have rounder nose and eye cavities, andjaws that protrude forward, whereas Caucasians and East Asians have flatter faces. Caucasian skullsare longer, have larger chinbones and tear-shaped nose openings. East Asian skulls tend to be shortand broad with wide cheekbones. There are many other features characteristic of the three skull types.As is often the case, there is no single feature that suffices to assign a skull to a particular racial type;rather, each feature is more common in one race than the others, allowing a combination of suchfeatures to be diagnostic.

By taking just a few measurements, physical anthropologists can tell police departments the raceof a skull’s former owner with better than 80% accuracy. This ability has occasioned some anguishamong those persuaded by Montagu that human races shouldn’t be acknowledged. How could theyidentify a skull’s race so accurately if race doesn’t exist? “That forensic anthropologists place ourfield’s stamp of approval on the traditional and unscientific concept of race each time we make such ajudgement is a problem for which I see no easy solution,” wrote one physical anthropologist. Hissuggestion was to obfuscate, by retaining the concept but substituting a euphemism for the word race,such as ancestry.9 This advice has been followed by a wide range of researchers who, while retainingthe necessary concept of race, refer to it in print with bland periphrases like “population structure” or“population stratification.” As for the actual DNA elements now used by biologists to assign people

to their race, or races if of mixed parentage, these are known discreetly as AIMs, or ancestryinformative markers.

Evolution and Speciation

Races are a way station on the path through which evolution generates new species. The environmentkeeps changing, and organisms will perish unless they adapt. In the course of adaptation, differentvariations of a species will emerge in conditions where the species faces different challenges. Thesevariations, or races, are fluid, not fixed. If the selective pressure that brought them into being shoulddisappear, they will merge back into the general gene pool. Or, if a race should cease to interbreedwith its neighbors through the emergence of some barrier to reproduction, it may eventually become aseparate species.

People have not been granted an exemption from this process. If human differentiation were tocontinue at the same pace as that of the past 50,000 years, one or more of today’s races might in thedistant future develop into a different species. But the forces of differentiation seem now to havereversed course due to increased migration, travel and intermarriage.

Races develop within a species and easily merge back into it. All human races, so far as isknown, have the same set of genes. But each gene comes in a set of different flavors or alternativeforms, known to geneticists as alleles. One might suppose that races differ in having different allelesof various genes. But, though a handful of such racially defining alleles do exist, the basis of racerests largely on something even slighter, a difference in the relative commonness, or frequency, ofalleles, a situation discussed further in the next chapter.

The frequency of each allele of a gene changes from one generation to the next, depending on thechance of which parent’s allele is inherited and whether the allele is favored by natural selection.Races are therefore quite dynamic, because the allele frequencies on which they depend are shiftingall the time. A good description is provided by the historian Winthrop Jordan in his history of thehistorical origins of racism in the United States. “It is now clear,” he writes, “that mankind is a singlebiological species; that races are neither discrete nor stable units but rather that they are plastic,changing, integral parts of a whole that is itself changing. It is clear, furthermore, that races are beststudied as products of a process; and, finally, that racial differences involve the relative frequency ofgenes and characteristics rather than absolute and mutually exclusive distinctions.” 10

Races emerge as part of the process of evolutionary change. At the level of the genome, thedriving force of evolution is mutation. Mutation generates novelty in the sequence of DNA units thatcomprise the hereditary information. The new sequences are then acted on—either eliminated, mademore common or ignored—by the evolutionary processes of natural selection, genetic drift andmigration.

The chemical units of which DNA is composed are long lasting but not permanent. Every so often,from spontaneous decay or radiation, a unit will disintegrate. In every living cell, repair enzymesconstantly patrol up and down the strands of DNA, proofreading the sequence of chemical units, orbases, as chemists call them. The four bases are known for short as A (adenine), T (thymine), G(guanine) and C (cytosine). The structure of a DNA molecule consists of two strands that spiralaround each other in a double helix, with each base on one strand lightly cross-linked to a base on theother strand. The cross-linking system requires that where one strand of the double helix has A, therewill be a T at the same site on the opposite strand, with G and C being similarly paired. If the baseopposite a T is missing, the repair enzymes know to insert an A. If a C is missing its partner, the

enzymes will provide a G. The system, though amazingly efficient, is not perfect. A wrong base isoccasionally inserted by the proofreading system, and these “typos” are called mutations. When themutations happen to occur in a person’s germ cells, whether eggs or sperm, they becomeevolutionarily significant, because they may then get passed on to the next generation.

Other kinds of mutation occur through copying errors made by the cell in manipulating DNA. Allthese types of mutation are the raw material for natural selection, the second evolutionary force. Mostmutations affect only the copious regions of DNA that lie between the genes and are of littleconsequence. It’s the sequence of bases in the genes that codes the information that specifies proteinsand other working parts of the cell. This coding DNA, as it is called, occupies less than 2% of thehuman genome. Mutations that do not meaningfully alter the coding DNA or the nearby promoterregions of DNA, used to activate the coding DNA, generally have no effect on the organism. Naturalselection has no reason to bother about them, and for this reason geneticists call them neutralmutations.

Of the mutations that do change the genetic sequence, most degrade or even destroy the function ofthe protein specified by the gene. These mutations are detrimental and need to be eliminated.“Purifying selection” is the phrase geneticists use for the action of natural selection in ridding thegenome of harmful mutations. The bearer of the mutation fails to live or has few or no offspring.

It’s just a handful of mutations that have a beneficial effect, and these become more common in thepopulation with each succeeding generation as the lucky owners are better able to survive and breed.

The individuals with a beneficial mutation possess a new gene, or rather a new allele—a versionof the old gene with the new mutation embedded in it. It’s because of mutations and alleles that thereexists a third force of evolutionary change, called genetic drift. Each generation is a genetic lottery.Your father and mother each have two copies of every gene. Each parent bequeaths one of their twocopies to you. The other is left on the cutting room floor. Suppose that with a particular gene there arejust two versions, called alleles A and B, in a population. Suppose too that 60% of a presentpopulation carries allele A and 40% allele B. In the next generation, these proportions will changebecause, by the luck of the draw, allele A will be passed on to children more often than allele B, orthe other way round.

If you follow the fate of allele A down the generations, it does a random walk in terms of itsfrequency in the population, from 60% in one generation, say, to 67% in the next to 58% to 33% andso on. But the walk cannot continue forever, because sooner or later it will hit one of two numbers,either 0% or 100%. If the frequency falls to 0%, allele A is permanently lost from the population. If ithits 100%, it’s allele B that is lost and allele A that becomes the permanent form of the gene, at leastuntil a new and better mutation crops up. This fluctuation in frequency is a random process known asgenetic drift, and when the walk ends in allele A hitting 100%, geneticists say that it has become fixedor has gone to fixation, meaning it’s the only game in town.

An important part of the genome that has gone to fixation is the DNA of the energy-producingmitochondria, former bacteria that were captured and enslaved long ago by the ancestor of all animaland plant cells. The mitochondria, little organelles within every cell, are inherited through the egg andpassed down from a mother to her children. At some early stage in modern human evolution, onewoman’s mitochondrial DNA went to fixation by edging out all other versions of mitochondrial DNA.

The same winner-take-all victory was attained by a particular version of the Y chromosome,which men alone carry because it includes the male-determining gene. At a time when the human

population was quite small, a single individual’s Y chromosome increased in frequency until itbecame the only one left. As described below, the genetic legacies of the mitochondrial Eve and theY-chromosomal Adam have proved immensely useful for tracing the migration of their descendantsaround the globe.

This rise and fall of the alleles depends on the blind chance of which are cast aside and whichpass into the next generation when the egg and sperm cells are created. Genetic drift can be apowerful force in shaping populations, particularly small ones, in which the drift toward either lossor fixation can happen within a few generations.

Another force that shapes the genetic heritage of a species is migration. As long as a populationstays together and interbreeds, everyone draws from a common gene pool in which each gene existsin many different versions or alleles. An individual, however, can carry at most two alleles of eachgene, one from each parent. So if a group of individuals breaks off from the main population, it willcarry away only some of the alleles in the general pool, thus losing part of the available geneticendowment.

Mutation, drift, migration and natural selection are all unceasing forces that drive the engine ofevolution ever onward. Even if a population stays in the same place and its phenotype, or physicalform, remains the same, its genotype, or hereditary information, will remain in constant flux, runninglike the Red Queen to stay in the same place.

A population can stay more constant if it interbreeds, with everyone drawing from the same poolof alleles. As soon as any barrier to interbreeding occurs, such as a river encountered as the speciesspreads out, the populations on either side of the river will become subtly different from each otherbecause of genetic drift. They will have taken the first step toward becoming subspecies, or races,and will continue to accumulate minor differences. Eventually one of these minor differences, perhapsa shift in the season of mating or in mate preference, will create a reproductive barrier between thetwo subspecies. As soon as individuals in the two populations cease to mate freely, the twosubspecies are ready to split into distinct species.

The Peopling of the World

So consider how this mechanism of differentiation, of a species developing into races, would haveapplied to humans. The change agents of migration, drift and natural selection bore down on thehuman population with particular force as soon as people started to disperse from the ancestralhomeland. Those leaving Africa seem to have comprised a few hundred people, consisting perhaps ofa single hunter-gatherer band. They took with them only a fraction of the alleles in the ancestral humanpopulation, making them less genetically diverse. They spread across the world by a process ofpopulation budding. When a group grew too big for the local resources, it would split, with one bandstaying put and the other moving a few miles down the coast or upriver, a process that further reducedthe diversity at each population split.

Because the modern humans of 50,000 years ago were a tropical species, the first people to leaveAfrica probably crossed the southern end of the Red Sea and kept to roughly the same latitude,hugging the coast until they reached Sahul, the Ice Age continent that then included Australia, NewGuinea and Tasmania. The earliest known modern human remains outside Africa, about 46,000 yearsold, come from Lake Mungo in Australia.

The modern human exodus from Africa occurred at a time when the Pleistocene Ice Age hadanother 40,000 years to run. To begin with, hunter-gatherer bands were probably stretched outthrough a strip of mostly tropical climates from northeast Africa to India to Australia. To judge by thebehavior of modern hunter-gatherers, these little groups would have been highly territorial andaggressive toward neighbors. To get away from one another and find new territory, bands startedmoving north into the cold forests and steppes of Europe and East Asia.

The evolutionary pressures for change on these small isolated groups would have been intense.Those migrating eastward faced new environments. Living by hunting and gathering, they would havehad to relearn how to survive in each new habitat. The groups moving northward from the equatorialzone of the first migration would have encountered particularly harsh pressures. The last ice age didnot end until 10,000 years ago. The first modern humans who moved northward had to adapt toconditions very different from those of their tropical homeland and develop new technologies, such asmaking tightly fitting clothes and storing food for the winter months. The climate was far colder, theseasonal differences were more pronounced and the problems of keeping warm and findingsustenance during the winter months were severe.

If these obstacles were not daunting enough, the people moving northward encountered armedopposition as well. An earlier wave of humans had left Africa some 500,000 years before and nowoccupied the Eurasian continent. These humans, called archaic to distinguish them from modernpeople, included the Neanderthals in Europe and Homo erectus in East Asia. Both disappeared aboutthe time that modern humans entered their territories. In the case of the Neanderthals, thearchaeological record makes clear that the area of their settlements steadily shrank as that of themodern humans increased, implying that the moderns drove the Neanderthals to extinction. The recordfrom East Asia is not yet detailed enough for the fate of Homo erectus to be understood, but a strongpossibility is that the species met the same fate as the Neanderthals.

After the occupation of Eurasia, the single gene pool that existed among the small group that leftAfrica was now fragmented into many different pools. The vast terrain across which humans were

now spread, from southern Africa to Europe, Siberia and Australia, prevented any substantial flow ofgenes between them. Each little population started to accumulate its own set of mutations in additionto those inherited from the common ancestral population. And in each population the forces of naturalselection and drift worked independently to process these mutations, making some more common andeliminating others.

If marriage partners had been exchanged freely throughout the human population as it dispersedaround the globe, races would never have developed. But the opposite was the case. People as theyspread out across the continents at the same time fragmented into small tribal groups. The mixing ofgenes between these little populations was probably very limited. Even if geography had not been aformidable barrier, the hunter-gatherer groups were territorial and mostly hostile to strangers. Travelwas perilous. Warfare was probably incessant, to judge by the behavior of modern hunter-gatherers.Other evidence of warfare lies in the slow growth of the early human population, which was farbelow the natural birth rate and could imply a regular hemorrhage of deaths in battle.

Once the available territory had been occupied, people overwhelmingly lived and died in theregion where they were born. The fact that people were pretty much locked within their hometerritories until modern times is one of the surprises that has come out of the genome. Several lines ofevidence point to this conclusion. All men carry copies of the same original Y chromosome, which,as mentioned above, became universal early in modern human evolution. But mutations started toaccumulate in the Y, and each mutation forms a branch point on the human family tree between themen who have it and the men who don’t. The root of this branching tree lies in Africa, and its limbsextend around the world in a pattern that follows the path of human migrations. There is not a lot oftangling between the branches, showing that the world filled up in an orderly way and that once it haddone so, people then stayed put.

The same story is told by the mitochondrial DNA in tracking the migration of women. Morerecently, geneticists have been able to survey populations using devices called gene chips that samplethe whole genome and provide a much more detailed picture. The gene chips are arrays of shortlengths of DNA chosen to recognize half a million sites along the human genome where the sequenceoften varies. (The variable sites, known as SNPs, or “snips,” tell where people differ; the sites on thegenome where everyone has the same DNA unit are uninformative.) Because two pieces of DNA willlink up chemically if their sequence of bases is exactly complementary* to each other, each shortpiece of DNA on a gene chip in effect interrogates the genome being tested, saying, “Do you have anA at this site or not?” Thus an entire genome can be scanned to test its sequence at sites that areknown to vary from one population to another.

Using a 500,000 snip chip, researchers at Stanford University have found a strongcorrespondence between the genetics and geographical origins of Europeans. In fact, 90% of peoplecan be located to within 700 kilometers (435 miles) of where they were born, and 50% to within 310kilometers (193 miles). Europeans are fairly homogeneous at the genetic level, so it is quitesurprising that enough genetic differences exist among them to infer a person’s origin so precisely.11

Another group of researchers looked at Europeans in isolated regions who weren’t likely to movemuch. One site was a Scottish island, another a Croatian village and the third an Italian valley.Anyone who didn’t have all four grandparents living in the same region was excluded. Under theseconditions, the researchers found they could map individuals to within 8 to 30 kilometers (5 to 19miles) of their village of origin.

The finding shows that the world’s human population is very finely structured in each geographicregion in terms of its genetics, with human genomes changing recognizably every few miles across theglobe. Such a situation exists only because, until the past few decades, most people have takenmarriage partners from very close to where they were born. Such a high degree of local marriage“was probably the norm in rural Europe due to lack of transport or economic opportunities,” theresearchers conclude.12

Evolutionary Stresses

Once the human population had spread out across the globe, it was subject to a variety of strongevolutionary stresses in the form of a radical makeover of human social organization and populationmovements that swept over the original settlement pattern. These population shifts were caused byclimate change, the spread of agriculture and warfare.

A clue to major population movements after the exodus from Africa is provided by human skincolor, which evolved to be dark in equatorial latitudes and pale in northern ones. If one could look atthe global population of 25,000 years ago, its differentiation might have been much simpler to trace.Agriculture hadn’t yet been invented, and population growth had not yet seriously upset the socialstructure of small hunter-gatherer groups. Anyone who could have flown around the globe would haveseen dark-skinned people inhabiting its equatorial belt, pale-skinned people in its high northernlatitudes and a smooth gradation of skin color between them.

What fractured this smooth pattern of association between skin color and latitude? By 25,000years ago, the Pleistocene Ice Age was nearing its end but was by no means exhausted. The glaciersadvanced south one more time, causing the extra cold period known as the Last Glacial Maximum.For the next 5,000 years or so, most of Europe and northern Siberia became uninhabitable. The light-skinned people living in northern latitudes did not wait for the glaciers to bury them. They movedsouth ahead of the advancing ice fields and as they did so they displaced and probably killed thedarker-skinned people to the south of them. The southerners, after all, would hardly have welcomedinvasion of their territory and would have defended it to the last. But the northerners would have hadthe advantage of being genetically and culturally adapted to living in the extreme cold thataccompanied them south. Moving ahead of the glaciers, they would have experienced a coolingenvironment to their liking but arduous for the people whom they were able to displace.

In Europe the retreating northerners found refuges from the cold in Spain and southern France.When the glaciers retreated, starting around 20,000 years ago, both Europe and East Asia wererepopulated by former northerners who had survived the Last Glacial Maximum in the southernrefuges they had wrested from their previous inhabitants. In this way both Europe and East Asia cameto be populated by people with pale skins, the descendants of those who had once lived in the highnorth.

Another two continents fell into the possession of the pale-skinned northerners around 15,000years ago, when conditions became warm enough for people living in Siberia to inhabit Beringia, thenow sunken landmass that once connected Siberia to Alaska. Perhaps as sea levels rose, some of theinhabitants of Beringia crossed over to Alaska. From there, once the ice sheets melted to open acorridor, they migrated southward to colonize the two continents of North and South America.

Also around 15,000 years ago, there began another process that marked a profound step in theevolution of human social structure—the emergence of the world’s first permanent settlements. Theseappeared independently in Europe, East Asia, Africa and the New World. For the previous 185,000years, ever since modern humans first appeared in the archaeological record, they had lived ashunters and gatherers. Now, for the first time, people were able to settle down in permanentcommunities, construct shelters and accumulate property.

The decision to settle cannot have been in any way simple or a matter of pure volition, or it

would have taken place many millennia previously. Most likely a shift in social behavior wasrequired, a genetic change that reduced the level of aggressivity common in hunter-gatherer groups.The human fossil record shows that in the period prior to settlement, there had been a gradual thinningof the human skeleton, a process known to physical anthropologists as gracilization. Gracilizationtypically occurs in the skeletons of wild animal species as they become domesticated. It seems thathumans underwent a similar lightening of their bone structure for the same reason—that they werebecoming less aggressive. Like animals undergoing domestication, humans shed bone mass becauseextreme aggressivity no longer carried the same survival advantages, and the most bellicose membersof a society were perhaps killed or ostracized. This profound change in social behavior was anecessary precursor to settling down in large communities and learning to get along with people whowere not close relations.

The first of these settled societies was the Natufian culture of the Near East, which appears in thearchaeological record some 15,000 years ago. Several thousand years after the first settlements,people found themselves inventing agriculture—somewhat inadvertently, because the process ofharvesting wild grasses automatically selected for strains more suitable to agriculture. As the climatewarmed toward the end of the Pleistocene Ice Age some 10,000 years ago, the incipient systems ofagriculture took off, centered on wheat and barley in the Near East and on millet and then rice inChina. With the new and more abundant sources of food, population started to increase, and the newfarmers expanded their territories. Increased population enhanced social stratification and disparitiesof wealth within societies, and a brisker tempo of warfare among them. Human social behavior had toadapt to a succession of makeovers as settled tribes developed into chiefdoms, chiefdoms intoarchaic states and states into empires.

These population expansions vastly changed the pattern of human distribution around the globe.Linguists like to distinguish between what they call mosaic zones and spread zones. The mostspectacular mosaic zone still in existence is that of New Guinea. The thickly forested territory isoccupied by people who, when discovered by Europeans, were using Stone Age technology andembroiled in endemic warfare. The island’s population is separated by territory and by culture. Every5 to 10 miles, a different language is spoken; the island is home to some 1,200 languages, one-fifth ofthe world’s total. Language is seen as a badge of identity and is deliberately made as different aspossible from that of neighboring tribes. Until warfare was supressed by colonial administrators,most New Guineans could not safely travel beyond their native valley.

In contrast to New Guinea with its 1,200 different languages, the United States is a spread zone,because a single language has been spoken from one coast to another since English speakersconquered the original inhabitants with their mosaic zone of many different languages. Much the samekind of process has probably operated throughout the past 50,000 years in a cycle between mosaiczones and spread zones.

When the world outside Africa was first occupied, it would have crystallized, much like the NewGuinea linguistic mosaic zone, into many thousands of territories, each occupied by a single tribe.With the passage of time, the language of each tribe would have become more unique and less likethat of its neighbors, and its genetics too would have become more distinctive. In each small tribe,different alleles would have drifted up in frequency to fixation or down to extinction.

Why then isn’t the global human population far more varied than it is? Because most of thesesmall tribes were destroyed or absorbed into larger tribes as spread zones, propelled by

demographic expansion or conquest, rolled like a wave over vast areas of mosaic zone. In Europe,for instance, people bringing the new farming technology from Anatolia, the region now known asTurkey, created a vast spread zone as they overwhelmed the existing hunter-gatherer populations, inpart by conquest, in part by intermarriage. An alternative hypothesis is that the spread zone wascreated by conquest, not the spread of agriculture, as warlike pastoralists from the Russian steppeburst out from their homeland and across Europe and India. In either case, the spread zone reflects theexpansion of people who spoke an ancestral tongue, Indo-European, and whose descendants nowspeak the many languages of the Indo-European family, from Icelandic and Spanish to Iranian andHindi.

In the Far East too, the rice farmers started to expand, killing the neighboring populations orabsorbing them through sheer pressure of numbers. The rise of the Han Chinese to become theworld’s largest population began just 10,000 years or so ago, this being the time when Mongoloid-type skulls first appear in the archaeological record. The demographic spread of the Han Chinese isstill under way, with less numerous neighbors like Tibetans and Uigur Turks finding themselvessteadily absorbed into the Han demographic imperium. In Africa, the Bantu expansion is anotherinstance of a spread zone formed by an agriculturally driven population increase. Many of today’sraces and ethnic groups were probably once small tribes that expanded through population increase,followed by conquering and absorbing outnumbered peoples.

All these evolutionary and historical processes took place independently in each continentalpopulation, since there was little flow of people or genes among them. Many salient changes in socialbehavior—the transition to settled life, the increasing social complexity from village to empire—aswell as the engulfment of smaller populations by larger ones, were parallel developments on eachcontinent, although they took place on a different schedule. The first known settlements were in theNear East, followed by those of China, Africa and the Americas. The difference in timing probablydepended on population. The denser the population on each continent, the greater the pressure forsettlement and the emergence of larger social groups.

Because the genes underlying social behavior are for the most part unknown, the parallel andindependent evolution of such genes in the various races cannot yet be demonstrated. But the paralleldevelopment of another trait, that of pale skin in East Asians and Europeans, as described below, cannow be tracked at the level of the relevant genes.

A Three Way Split

The emigration from Africa marked the first known major division in the modern human population,between those who remained in Africa and those who left. After the split, the two populations nolonger shared a common gene pool, being sharply separated by geography. Migrations back intoAfrica occurred later, but the numbers of people were far too small to remix the gene pool. Thoseoutside Africa and those within continued to evolve but along different pathways as each adapted toits special set of circumstances.

The next major fork in the human family tree occurred between the populations that colonized thetwo major halves of the Eurasian continent. Migrants to the north became the ancestors of Caucasiansin the west and of East Asians in the east. Caucasians include Europeans, Middle Easterners and thepeople of the Indian subcontinent. The term Caucasian is avoided by some anthropologists becauseBlumenbach, who invented the term, believed the inhabitants of the Caucasus were the world’s mostbeautiful people. But Blumenbach, as noted earlier, did not believe Caucasians were superior toother races. Because there is no other word to refer to this important grouping of populations, manygeneticists use this term.13 The date of the split between East Asians and Caucasians is still uncertainbut may have been as long as 30,000 years ago.

Both Caucasians and East Asians have light skin, an adaptation to living in high northern latitudes.The default state of primate skin is pale: chimpanzees, under their fur, have white skin (although theirfaces are dark because of heavy suntan). When our distant ancestors lost their fur, probably becausebare skin allowed better sweating and heat control, they developed dark skin to protect a vitalchemical known as folic acid from being destroyed by the strong ultraviolet light around the equator.The first modern humans who migrated to the northern latitudes of Europe and Asia were exposed tomuch less ultraviolet light—too little, in fact, to synthesize enough vitamin D, for which ultravioletlight is required. Natural selection therefore favored the development of pale skin among peopleliving in high northern latitudes. Pale skin may also have been prized in sexual partners, in whichcase sexual selection, as well as the need to synthesize vitamin D, would have speeded the spread ofthe necessary alleles. Objectively speaking, pale skin is no more attractive than any other shade. Ifanything, it is probably less so, to judge by the existence of tanning salons. It could have been prizedfor arbitrary reasons or, given its association with vitamin D synthesis, because its owners hadhealthier children in extreme northern latitudes.

Pale skin evolved independently in the Caucasian and East Asian populations, showing that thetwo populations have remained substantially separate since their split. This is known to be the casebecause pale skin in Caucasians is caused by a largely different set of genes than those that cause paleskin in East Asians. The independent but parallel evolution of pale skin in the two halves of theEurasian continent came about because each was exposed to the same stress—the need to protectvitamin D synthesis in northern latitudes. But natural selection can work only with whatever alleles—the different versions of a gene—are present in a population. Evidently different alleles for makingpale skin were available in the Caucasian and East Asian populations. This is not so surprising.Making, packaging and distributing the granules of pigment that give skin its color is a complexprocess, and there are many ways it can be tweaked so as to yield a particular outcome.

Among Africans, dark skin is maintained by the gene known as MC1R. A single version of this

gene is found throughout Africa, whereas at least 30 alleles, all different from the African allele, arefound among Europeans, and other variants are special to East Asians. It seems that any mutations orchanges in the African allele of MC1R lead to lighter skin, which is harmful in the African context.Carriers of such an allele in Africa have no or fewer children, and the variant versions of the MC1Rgene that keep cropping up because of mutation are constantly eliminated by purifying selection.14

Europeans have pale skin in part because purifying selection on their MC1R gene has beenrelaxed. But this is not the only reason. They have several alleles that promote pale skin. One is anallele of the gene known as SLC24A5. The SLC24A5 gene specifies a large protein—a chain ofamino acid units—in which the 111th unit is the amino acid known as alanine. This is the ancestralform of the gene and is the allele found in almost all Africans and East Asians. Almost all Europeanshave an allele in which there is a critical difference in the triplet of three consecutive DNA bases,known as a codon, that specifies the 111th amino acid unit. Different codons determine the 20 kindsof amino acid unit of which proteins are composed. In the case of the SLC24A5 gene, the 111th codonin the ancestral allele is the triplet of bases ACA, which specifies the amino acid alanine. InEuropeans, the first A in the triplet has mutated to a G, giving the sequence GCA, and this codonspecifies the amino acid known as threonine. This single switch of amino acids alters the function ofthe protein.

Almost all Europeans have two copies (one from each parent) of the threonine-denoting, skin-lightening allele of the SLC24A5 gene. Africans have two copies of the alanine allele that darkens theskin. African Americans and African Caribbeans who have one copy of each allele have intermediatehues of skin.15

East Asians have skin that can be just as pale as that of Europeans. But East Asians carry theancestral dark skin form of SLC24A5. Natural selection has found other routes by which to lighten theskin of East Asians.

Several other differences are already known between East Asians and Europeans, testifying to theancient split between the populations. One is the greater thickness of East Asian hair. Africans andEuropeans, who have thin hair shafts, carry the same version of a gene called EDAR. A differentallele is widespread in East Asians, occurring in 93% of Han Chinese, about 70% of people in Japanand Thailand, and in 60 to 90% of Native Americans. In the 370th codon of the gene, a T has mutatedto C, so that the amino acid coded for is alanine instead of valine.16 Because of the switch of valine(V) to alanine (A) at the 370th codon, the allele is called EDAR-V370A.

East Asians who carry the EDAR-V370A allele also have thick and lustrous hair. But correlationis not proof, so how can one be certain that EDAR-V370A is indeed the cause of East Asians’ thickhair shafts? Researchers who wished to prove this point recently generated a strain of mice whoseEDAR gene was converted to the East Asian form. They found the mice had thicker hair, proving thatthe allele is the cause of thick hair in East Asians, but also noticed two other interesting changes.17

First, the mice had more eccrine sweat glands than usual in their foot pads. Sweat glands come intwo versions, eccrine glands, which secrete water so as to cool the body by evaporation, andapocrine glands, which secrete proteins and hormones. Checking in a Chinese population, theresearchers found that the EDAR-V370A causes people too to carry significantly more eccrineglands, a fact that had been previously unknown.

The mice also had smaller breasts than usual, indicating that the EDAR-V370A allele is probablythe reason why East Asian women tend to have smaller breasts than African and European women.

A fourth probable effect of EDAR-V370A is that it causes the characteristic dentition of EastAsians, whose front teeth look shovel shaped when seen from the back. The mice were less useful inelucidating this effect because their teeth are so different from human teeth.

It may seem surprising that a single gene can have so many profound effects. EDAR has greatinfluence on the body because it is switched on early in embryonic development and helps shapeorgans such as the skin, teeth, hair and breasts.

The fact that the EDAR-V370A allele has so many effects in East Asians raises the intriguingquestion of which particular effect was the target of the natural selection that made the allele socommon. One possibility is that thick hair and small breasts were much admired by Asian men, orequally that thick hair in either sex was attractive to the other. In either case, these traits would havebeen acting as agents of sexual selection, a particularly potent form of natural selection.

Another possibility is that the sweat glands were the driving force behind the rise of EDAR-V370A. East Asians are usually assumed to have evolved in a cold climate because of certain traits,such as narrow nostrils and a fold of fat over the eyelid, which seem helpful in conserving body heat.But researchers have calculated that the EDAR variant emerged some 35,000 years ago, at whichtime central China was hot and humid.

A third possibility is that many or all of the effects of EDAR-V370A were advantageous at onetime or another, and that natural selection favored each in turn. Effects of less obvious advantage,such as the shaping of the teeth, were dragged along in the wake of the traits found favorable bynatural selection.

EDAR-V370A explains a substantial part, but not all, of the physiological differences betweenEast Asians and other races. Another feature that distinguishes most East Asians from Europeans andAfricans has to do with earwax. This substance comes in two forms, wet and dry. The switchbetween the two types is controlled by two alleles of the gene ABCC11. The allele that causes dryearwax is very common in East Asia. Among the northern Han Chinese and Koreans, 100% of peoplehave the dry allele. The percentage drops to 85% among the southern Han and to 87% in Japan.18

Almost all Europeans and all Africans have the wet earwax allele of the ABCC11 gene. Thissharp differentiation of the two alleles implies a strong selection pressure. But the function of earwax,like flypaper, is merely to deter insects from crawling into the ear. It seems unlikely that so minor arole would be critical to survival. But as it happens, the two alleles of the ABCC11 are also involvedin the apocrine sweat glands.

Unlike the eccrine sweat glands mentioned above, which are found all over the body and secretejust water, the apocrine glands in humans are restricted after birth to just the armpits, nipples, eyelidsand other special niches. They make slightly oily secretions, and the specialty of those in the ear is tosecrete earwax. The apocrine gland secretions are odorless at first but produce body odor after beingdecomposed by the bacteria ubiquitous on the skin.

East Asians with the dry earwax allele of the gene produce fewer secretions from their apocrineglands and as a result have less body odor. Among people spending many months in confined spacesto escape the cold, lack of body odor would have been an attractive trait and one perhaps favored bysexual selection.

Yet another East Asian characteristic is the type of skull known to physical anthropologists asMongoloid. Mongoloid skulls have fine features, a broad head shape, and flattened faces. They alsohave a distinctive dentition. Africans and Europeans have the same kind of generic human teeth,

which is evidently the ancestral pattern. In the East a new tooth pattern emerged, called sundadontyafter Sunda, the Ice Age continent that disintegrated after the rise of sea level into Malaysia and theislands of Indonesia. Southeast Asians and the populations derived from them in Polynesia aresundadonts. Some 30,000 years ago, a variation of sundadonty appeared called sinodonty, in whichthe upper incisors are shovel shaped and some molar teeth have extra roots. Northern Chinese,Japanese and Native Americans, who are descended from Siberian populations, are all sinodonts.

Politically oriented scientists often proclaim that there are no distinct human races, seeking toimply, without actually saying so, that races do not exist. One reason that races exist, though notdistinctly, is that the features characteristic of a race are often distributed along a gradient. Almost allnorthern Chinese have the sinodont pattern of dentition, but the farther one goes toward southernChina and Southeast Asia, the greater the percentage of people who are sundadonts and the fewerwho are sinodonts. The dry earwax allele is almost universal in northern China but yields to the wetallele toward the south. Most East Asians have the dry earwax gene, but not all do. Most, but not all,have the EDAR-V370A allele.

All these differences are variations superimposed on the common human theme. Even smalldifferences in appearance can be of great social significance, given the strong human tendency todistinguish between the in-group and the out-group. Like the minor variations of language known asdialects, variations in skin or hair color can form the basis on which one group distinguishes itselffrom its neighbors. If intermarriage then ceases to occur across this fault line, other differences willaccumulate, pushing human populations toward differentiation and away from remixing into acommon genetic pool.

The Five Continental Races

Those who assert that human races don’t exist like to point to the many, mutually inconsistentclassification schemes that have recognized anywhere from 3 to 60 races. But the lack of agreementdoesn’t mean that races don’t exist, only that it is a matter of judgment as to how to define them. Aswith any species that evolves into geographically based races, there is usually continuity betweenneighboring races because of gene exchange between them. Because there is no clear dividing line,there are no distinct races—that is the nature of variation within a species. Nonetheless, usefuldistinctions can be made.

The first step in making sense of human variation and the emergence of races is to follow thehistorical succession of major population splits. As noted above, the first such split occurred when asmall group of people left northeast Africa some 50,000 years ago and populated the rest of theworld. The first major division in the human population is thus between Africans and non-Africans.(Africans here denotes people who live south of the Sahara, because those north of the Sahara arelargely Caucasian.) Among the non-Africans, there was an early division, whose nature is still poorlyunderstood, between Europeans and East Asians. This gives a three-way split in the humanpopulation that corresponds robustly to the three racial groups that everyone can identify at a glance,those of Africans, East Asians and Caucasians. The fact that other peoples may not be so easy toclassify does not alter the validity of these three basic categories.

The first migration out of Africa, the one that gave rise to both Europeans and East Asians,eventually reached Sahul, the ancient Ice Age continent that was split by rising sea levels into thethree landmasses of Australia, New Guinea and Tasmania. Australian aborigines, surprisingly, turnout to be a race unlike any other. They and their relatives in New Guinea have no trace in theirgenome of admixture with other races until the historical period. This implies that once Sahul wassettled, some 46,000 years ago, the residents fought off all later migrations until the arrival ofEuropeans in the 18th century. Australian aborigines can reasonably be considered a race, although aminor one in terms of population size, because of their distinctness, antiquity and the fact that theyinhabit a continent.

American Indians, the original inhabitants of North and South America, can also be considered arace. Their ancestors were Siberians who originally crossed into Alaska some 15,000 years ago, butAmerican Indians have diverged considerably since then.

A practical way of classifying human variation is therefore to recognize five races based oncontinent of origin. These are the three principal races—Africans, East Asians and Caucasians—andthe two other continent-based groups of Native Americans and Australian aborigines (including thepeople of New Guinea, an island joined to Australia until the end of the last ice age).

At the land boundaries where races meet, there are often intermarried or admixed populations, asgeneticists call them. Palestinians, Somalis and Ethiopians, for instance, are admixtures of Africanand Caucasian populations. The Uigur Turks of northwestern China and the Hazara of Afghanistan areadmixtures of Caucasian and East Asian populations. African Americans are an admixture mostly ofAfricans and Caucasians.

Within each continental race are smaller groupings which, to avoid terms like subrace orsubpopulation, that might be assumed to imply inferiority, may be called ethnicities. Thus Finns,

Icelanders, Jews and other groups with recognizable genetics are ethnicities within the Caucasianrace.

Such an arrangement, of portioning human variation into five continental races, is to some extentarbitrary. But it makes practical sense. The three major races are easy to recognize. The five-waydivision matches the known events of human population history. And most significant of all, thedivision by continent is supported by genetics.

I

5

THE GENETICS OF RACE

Selfish and contentious people will not cohere, and without coherence nothing can be effected. A tribe rich inthe above qualities would spread and be victorious over other tribes: but in the course of time it would, judgingfrom all past history, be in its turn overcome by some other tribe more highly endowed. Thus the social andmoral qualities would tend slowly to advance and be diffused throughout the world.

—CHARLES DARWIN1

n the case of human races, the genetic differences from one race to another are slight and subtle.One might expect that different races would have different genes, but they don’t. All humans, sofar as is known, have the same set of genes. Each gene comes in various alternative forms,called alleles, so the next expectation might be that races would be distinguished by having

different alleles of various genes. But this too is not how the system works. There are a mere handfulof known cases where a particular allele of a gene occurs in only one race.

The genetic differences between human races turn out to be based largely in allele frequencies,meaning the percentages of each allele that occur in a given race. How a mere difference in allelefrequencies could lead to differences in physical traits is explained below.

Races as Clusters of Variation

A necessary approach to studying racial variation is to look not for absolute differences but at howthe genomes of individuals throughout the world cluster together in terms of their genetic similarity.The result is that everyone ends up in the cluster with which they share the most variation in common.These clusters always correspond to the five continental races in the first instance, though when extraDNA markers are used, the people of the Indian subcontinent sometimes split away from Caucasiansas a sixth major group, and people of the Middle East as a seventh.

One of the first genetic clustering techniques depended on examining an element of the genomecalled tandem repeats. There are many sites on the genome where the same pair of DNA units isrepeated several times in tandem. CA stands for the DNA unit known as a cytosine followed byadenine, so the DNA sequence CACACACA would be called a tandem CA repeat. The string ofrepeats occasionally confuses the DNA copying apparatus, which every few generations may add ordrop a repeat unit during the copying process that has to occur before a cell can divide. Sites at whichrepeats occur therefore tend to be quite variable, and this variability is useful for comparingpopulations.

In 1994, in one of the earliest attempts to study human differentiation in terms of DNAdifferences, a research team led by Anne Bowcock of the University of Texas and Luca Cavalli-Sforza of Stanford University looked at CA repeats at 30 sites on the genome in people from 14populations. Comparing their subjects on the basis of the number of CA repeats at each genomic site,the researchers found that people clustered together in groups that were coincident with theircontinent of origin. In other words, all the Africans had patterns of CA repeats that resembled oneanother, all the American Indians had a different pattern of repeats and so on. Altogether there were 5principal clusters of CA repeats, formed by people living in each of the 5 continental regions ofAfrica, Europe, East Asia, the Americas and Australasia.2

Many larger and more sophisticated surveys have been done since, and all have come to the sameconclusion, that “genetic differentiation is greatest when defined on a continental basis,” writes NeilRisch, a statistical geneticist at the University of California, San Francisco. “Effectively, thesepopulation genetic studies have recapitulated the classical definition of races based on continentalancestry—namely African, Caucasian (Europe and Middle East), Asian, Pacific Islander (forexample, Australian, New Guinean and Melanesian), and Native American.” 3

In one of these more sophisticated studies, a team led by Noah Rosenberg of the University ofSouthern California and Marcus Feldman of Stanford University looked at the number of repeats at377 sites on the genome of more than 1,000 people around the world. When this many sites areexamined on a genome, it’s possible to assign segments of an individual’s genome to different races ifhe or she has mixed ancestry. This is because each race or ethnicity has a characteristic number ofrepeats at each genomic site.

The Rosenberg-Feldman study showed, as expected, that the 1,000 individuals in their studyclustered naturally into five groups, corresponding to the five continental races. It also brought out thefact that several Central Asian ethnicities, such as Pathans, Hazara and Uigurs, are of mixed Europeanand East Asian ancestry. This is not a surprise, given the frequent movement of peoples to and froacross Central Asia.

Language is often an isolating mechanism that deters intermarriage with neighboring groups. TheBurusho, a people of Pakistan who speak a unique language, turn out also to be unlike their neighborsgenetically. Within races, the Rosenberg-Feldman study showed that different ethnicities could berecognized. Among Africans, it is easy to distinguish by their genomes the Yoruba of Nigeria, the San(a click-speaking people of southern Africa) and the Mbuti and Biaka pygmies.

Many populations are not highly mixed, and the Rosenberg-Feldman survey confirmed theremarkable extent to which people throughout history have lived and died in the place where theywere born.4

In the ancestral human population in Africa, a large number of alleles had developed for eachgene over many generations. Those who migrated out of Africa took away only a sample of thesealleles. And each time a new group split off, the number of alleles from the original population againdecreased.

The farther away from Africa that this process continued, the less was the diversity of alleles.This downhill gradient happens with any population that expands too far from its origins to maintainthe regular interbreeding that keeps the gene pool well mixed.

A genetic gradient, or cline, is what some researchers prefer to think exists in place of races.“There are no races, there are only clines,” asserted the biological anthropologist Frank Livingstone.5Critics raised the same objection against the Rosenberg-Feldman result, alleging that the clustering ofindividuals into races was an artifact and that with a geographically more uniform samplingapproach, the researchers would have seen only clines.6 The Rosenberg-Feldman team thenreanalyzed their data and gave their survey finer resolution by looking at 993 sites, not just 377, oneach of the genomes in their study. They found that the clusters are real. Although there are gradientsof genetic diversity, there is also a clustering into the continental groups described in their firstarticle.7

Rosenberg and Feldman compared people’s genomes on the basis of DNA repeats. Another kindof DNA marker has since become available for global population comparison—the SNP, which ismore useful for medical studies. SNP stands for single nucleotide polymorphism, meaning a site onthe genome where some people have a different kind of DNA unit from that of the majority. A vastpreponderance of sites on the genome are fixed, meaning everyone has the same DNA unit, whetherA, T, G or C. The fixed sites, being all the same, say nothing about human variation. It’s the SNPsites, which are variable, that are of particular interest to geneticists because they afford a direct wayof comparing populations. To exclude the many random mutations that occur just in particularindividuals and have no wider importance, SNPs are arbitrarily defined as sites on the genome whereat least 1% of the population has a DNA unit other than the standard one.

A research group led by Jun Z. Li and Richard M. Myers has applied a clustering program likethat used by Rosenberg and Feldman to almost 1,000 people in 51 populations across the globe. Eachperson’s genome was examined at 650,000 SNP sites. On the basis of SNPs, just as with the DNArepeats, people sampled from around the world clustered into 5 continental groups. But in addition,the SNP library brought to light two other major clusters. These had not emerged in the Rosenberg-Feldman study, which had used fewer markers. The more DNA markers that are used, whether tandemrepeats or SNPs, the more subdivisions can be established in the human population.

One of the new clusters is formed by the people of Central and South Asia, including India andPakistan. The second is the Middle East, where there is considerable admixture with people from

Europe and Africa.8 It might be reasonable to elevate the Indian and Middle Eastern groups to thelevel of major races, making seven in all. But then many more subpopulations could be declaredraces, so to keep things simple, the five-race, continent-based scheme seems the most practical formost purposes.

Within each continental race, the SNP analysis could separate out further subgroups. WithinEurope it distinguished French, Italians, Russians, Sardinians and Orcadians (people who live in theOrkney Islands, north of Scotland). In China the northern Han can be distinguished from the southernHan.

Groupings within Africa are of particular interest because this is where modern humans spent thefirst 150,000 years of their existence. In the most thorough survey of Africa so far, Sarah Tishkoff andcolleagues surveyed people from 121 populations, scanning their genomes at 1,327 variable sites,most of them DNA repeats. The survey brought to light 14 different ancestral groups within Africa.Tishkoff found that, unlike in the rest of the world, where there are definable continental races, inAfrica most populations are admixtures of several ancestral groups. There have presumably been alarger number of migration events within Africa, which served to mix up populations that wereoriginally separate. The most recent large-scale migration was the Bantu expansion, a populationexplosion driven by new agricultural technology. Within the past few thousand years, Bantu speakersfrom the region of Nigeria and Cameroon in West Africa have migrated across to eastern Africa anddown both coasts to southern Africa. Only a few groups have kept relatively clear of the churning ofpopulations within Africa. These include the click-speaking peoples of Tanzania and southern Africa,who until recently have been hunter-gatherers, and the various pygmy groups, who live deep in theforest.9

The click-speakers and pygmies may be remnants of a much earlier hunter-gatherer populationthat once occupied a large part of southern Africa and the eastern coast as far north as Somalia. Theclick-speakers speak a group of languages known as Khoisan, which are unlike any others and haveonly very distant relationships among themselves, probably reflecting their great antiquity. The pygmygroups too may once have spoken Khoisan languages but it is impossible to know for sure, becausethey have lost their original languages.

Africa has four language superfamilies, of which Khoisan is one and the other three are Niger-Kordofanian (also known as Niger-Congo), Nilo-Saharan and Afro-Asiatic. The Niger-Kordofanianlanguages, the most widespread, were carried from western to eastern Africa and then south by theBantu expansion, a great stream of migrations from the proto-Bantu homeland in western Africa thatbegan in about 1000 BC and reached southern Africa a thousand years later. Afro-Asiatic languagesare spoken in a broad belt across northern Africa, and the Nilo-Saharan speakers are sandwichedbetween Afro-Asiatic to the north and Niger-Kordofanian to the south.

Genetics generally correlates with language family, except in the case of populations that haveswitched languages; the pygmies now speak Niger-Kordofanian languages, and the Luo of Kenya,whose genetics place them with Niger-Kordofanian speakers, now speak a Nilo-Saharan language.

The Tishkoff team surveyed African Americans from Chicago, Baltimore, Pittsburgh and NorthCarolina and found that 71% of their genomes, on average, matched the genetics of Niger-Kordofanian speakers, 8% matched that of other African populations and 13% were European. Thesepercentages varied greatly from one individual to another.

The origin of a species can often be located by surveying the genetic diversity in its members and

seeing where diversity is highest. This is because the founding population will have had longest toaccumulate the mutations that generate diversity, and the groups that migrate away will carry withthem only a sample of the original mutations. (Other forces, like natural selection, reduce diversity byeliminating harmful mutations and sweeping away others when a beneficial mutation is favored.) Onthe basis of the new African and other genomic data, the origin of the modern human migration lies insouthwestern Africa, near the border of Namibia and Angola, in a region that is the current homelandof the San click-speakers. The finding is not definitive, because the distribution of ancient populationsmay have been rather different from those of today. Nonetheless, the fact that human genetics points toa single origin confirms that today’s races are all mere variations on the same theme.

Fingerprints of Selection in the Human Genome

Both repeated DNA units and SNPs, the two kinds of DNA marker used by the surveys describedabove, lie for the most part outside genes and have little or no effect on a person’s physical makeup.They are what geneticists call neutral variations, meaning that they are ignored by natural selection.What then is it that makes human populations differ from one another?

Natural selection is the major shaper of differences, especially in large societies. In smallsocieties, genetic drift—the luck of the draw as to which alleles make it into the next generation—canbe a significant influence. But natural selection, often in concert with drift, is a major force over thelong run. With the advent of fast methods of genome sequencing, geneticists have at last begun todelineate the fingerprints of natural selection in remodeling the human genome. These fingerprints areboth recent and regional, meaning that they differ from one race to another.

The regional nature of selection was first made evident in a genomewide scan undertaken byJonathan Pritchard, a population geneticist at the University of Chicago, in 2006. He looked for genesunder selection in the three major races—Africans, East Asians and Europeans (or more exactlyCaucasians, but European genetics are at present much better understood, so European populationsare the usual subjects of study). Copious genetic data had been collected on each race as part of theHapMap, a project undertaken by the National Institutes of Health to explore the genetic roots ofcommon disease. In each race Pritchard found about 200 genetic regions that showed a characteristicsignature of having been under selection (206 in Africans, 185 in East Asians and 188 in Europeans).But in each race, a largely different set of genes was under selection, with only quite minoroverlaps.10

The evidence of natural selection at work on a gene is that the percentage of the population thatcarries the favored allele of the gene has increased. But though alleles under selection become morecommon, they rarely displace all the other alleles of the gene in question by attaining a frequency of100%. Were this to happen often in a population, races could be distinguished on the basis of whichalleles they carried, which is generally not the case. In practice, the intensity of selection oftenrelaxes as an allele rises in frequency, because the needed trait is well on the way to being attained.

Geneticists have several tests for whether a gene has been a recent target for natural selection.Many such tests, including the one devised by Pritchard, rest on the fact that as the favored allele of agene sweeps through a population, the amount of genetic diversity in and around the gene is reducedin the population as a whole. This is so because increasing numbers of people now carry the samesequence of DNA units at that site, those of the favored allele. So the result of such a sweep is thatDNA differences between members of a population are reduced in the region of the genome affectedby the sweep. The concept of using sweeps as signatures of natural selection is discussed furtherbelow.

Figure 4.1. Regions of the genome that are highly selected in the three major races. ASN = East Asian, asample of Chinese and Japanese. YRI = Yoruba, a West African people. CEU = European.

FROM JONATHAN PRITCHARD, PLOS BIOLOGY 4(2006):446–58.

Other researchers too have found that in doing genome scans for the fingerprints of naturalselection, each major race or continental population has its own distinctive set of sites whereselection has occurred.

These sites of selection are often very large and contain many genes, making it hard or impossible

to decide which specific gene was the target of natural selection. In a new approach, which takesadvantage of the many whole genomes that have now been decoded, Pardis Sabeti of Harvard andcolleagues have defined 412 regions under selection in Africans, Europeans and East Asians. Theregions are so small that most contain one or no genes. Those without genes presumably contain acontrol element, meaning a stretch of DNA that regulates some nearby gene.11

Of the 412 regions of the human genome shown to be under selection, 140 were under selectionjust in Europeans, 140 in East Asians and 132 in Africans.12 The absence of any overlap, meaninggenes selected in two or more populations, as was found by Pritchard, is due to the Sabeti team’sgenome scanning method, which depended in part on looking for sites at which the three racesdiffered.

Each gene under selection will eventually tell a fascinating story about some historical stress towhich the population was exposed and then adapted. A case in point is the analysis of the EDAR-V370A allele which, as described in the previous chapter, is the cause of thick hair and other traits inEast Asians. But those narratives are for the moment inaccessible. The exploration of the humangenome is so much at its beginning that the precise function of most genes is unknown.

Still, even though the exact tasks of most genes are still uncertain, the general roles of most genescan be inferred by comparing the DNA sequence of any unknown gene with those of known genesrecorded in genomic data banks. The known genes are grouped into general functional categories, likebrain genes or genes involved in metabolism, and since function is related to structure, the genes ineach category have a characteristic sequence of DNA units. By comparing the DNA sequence of anynew gene with the data bank sequences, the gene can be assigned to a general functional category. Thegenes Pritchard identified as shaped by natural selection included genes for fertilization andreproduction, genes for skin color, genes for skeletal development and genes for brain function. In thebrain function category, four genes were under selection in Africans and two each in East Asians andEuropeans. What these genes do within the brain is largely unknown. But the findings establish theobvious truth that brain genes do not lie in some special category exempt from natural selection. Theyare as much under evolutionary pressure as any other category of gene.

Population geneticists have developed several different kinds of tests to see if natural selectionhas influenced the DNA sequence of a gene. All these tests are statistical, and many depend on thedisturbance in gene frequencies that is caused as a favored gene sweeps through a population. Naturalselection cannot pick out single genes or even single mutations in DNA. Rather, it depends on theprocess called recombination, in which the mother’s and father’s genomes are shuffled prior tocreating eggs and sperm.

In the egg-making or sperm-making cells, the two sets of chromosomes that a person has inherited,one from their mother and one from their father, are lined up side by side, and the cell then forcesthem to exchange large sections of DNA. These new composite chromosomes, consisting of somesections from the father’s genome and some from the mother’s, are what is passed on to the nextgeneration.

The swapped sections, or blocks, may be 500,000 DNA units in length, long enough to carryseveral genes. So a gene with a beneficial mutation will be inherited along with the whole block ofDNA in which it is embedded. It’s because beneficial genes lie in such a large block that the effect ofnatural selection on the genome can be detected—the favored blocks sweep out large regions of thegenome as they spread through a population.

Generation by generation, the block of DNA with the favored version of a gene gets to be carriedby more and more people. Eventually, the new allele may sweep through the entire population, inwhich case geneticists say it has gone to fixation. But most sweeps do not carry an allele to fixationbecause, as already noted, the intensity of selection on a beneficial allele relaxes as the trait ismolded toward its most efficient form.

Whether a sweep is complete or partial, the favored blocks of DNA eventually get whittled downover the generations, because the cuts that generate them are not always made in the same places onthe chromosome. After just 30,000 years or so, according to one calculation, the blocks get too shortto be detectable. This means that most genomewide scans for selection are looking at events thatoccurred just a few thousand years ago, very recently in human evolution.

Biologists have long had to depend on the evidence from fossils to judge the speed of evolution.But fossils capture just the bones of an animal. And since the skeletal structure of a species changesonly slowly, evolution has long seemed a glacially slow and plodding process.

With the ability to decode DNA sequences, biologists can examine the raw programming ofevolutionary change and track every gene in a species’ repertoire. It’s now clear that evolution is nosluggard. There are already clear examples of human evolutionary change within the past fewthousand years, such as Tibetans’ adaptation to high altitude, starting from just 3,000 years ago. Ofcourse, every gene in the human genome has been intensely shaped by natural selection at one time oranother. But with most genes, the selection was accomplished eons before humans or even primateshad evolved. The fingerprints of these ancient selection events have long since faded from sight. Thetype of selection picked up by most genome scans is very recent selection, meaning within the past5,000 to 30,000 years or so, but fortunately this is a period of great interest for understanding humanevolution.

More than 20 scans for selection have now been performed on the human genome. They do not allmark the same regions as being under selection but that is not surprising since the authors use differentkinds of tests and different statistical methods, which are in any case imprecise. But if one takes justthe regions marked by any two of the scans, then 722 regions, containing some 2,465 genes, have beenunder recent pressure of natural selection, according to an estimate by Joshua M. Akey of theUniversity of Washington. This amounts to 14% of the genome.13

That so much of the genome has been under natural selection strong enough to be detectableshows how intense human evolution must have been in the past few thousand years. A principaldriver of evolutionary change would have been the need to adapt to a wide range of newenvironments. In proof of that point, some 80% of the 722 regions under selection are instances oflocal adaptation, meaning that they occur in one of the three main races but not in the other two.

The genes under selection affect a large number of biological traits, prominent among them beingskin color, diet, bone and hair structure, resistance to disease and brain function.

A similar finding emerged from a particularly comprehensive genome scan conducted by MarkStoneking and colleagues. Stoneking, a population geneticist at the Max Planck Institute forEvolutionary Anthropology in Leipzig, is known for having developed an ingenious way of estimatingwhen humans first started to wear clothes. The body louse, which lives only in clothes, evolved fromthe head louse, which lives on hair. Stoneking realized that a date for the first tight-fitting clothescould be derived by using genetic methods to date the birth of the body louse lineage—about 72,000years ago.14

In his genome survey, Stoneking found many genes under selection that affected people’sinteraction with their environment, such as genes involved in metabolizing certain classes of food andgenes that mediate resistance to pathogens. Among the genes under selection he also found severalthat were involved in aspects of the nervous system, such as cognition and sensory perception.

The genes of the nervous system have been under selection for the same reason as the other genes—to help people adapt to local circumstances. Changes in social behavior may well have beenforemost, given that it is largely through their society that people interact with their environment.Signals of selection in brain genes “may be related to how different human groups interactbehaviorally with their environment and/or with other human groups,” Stoneking and colleagueswrote.15

Another regional trend indicated by the genome scans is that there seem to be more genes underselection in the genomes of East Asians and Europeans than in those of Africans. Not all genomescans have reported such a finding—the Pritchard scan described above did not—and Africanpopulations have been poorly sampled so far. But in a subsequent scan, Pritchard and others did findevidence for more sweeps outside Africa.

“A plausible explanation is that humans experienced many novel selective pressures as theyspread out of Africa into new habitats and cooler climates,” they wrote. “Hence there may simplyhave been more sustained selective pressures on non-Africans for novel phenotypes.” 16 Phenotyperefers to the physical trait or organism produced by the DNA, as contrasted with the DNA itself,which is known as the genotype. One obvious example of a novel phenotype needed outside Africa isthat of skin color. Africans have retained the default dark skin of the ancestral human population,whereas East Asians and Europeans, descendants of populations who adapted to extreme northernlatitudes, have evolved pale skin.

Both within Africa and in the world outside, social structure underwent a radical transition aspopulations began to grow after the beginning of agriculture some 10,000 years ago. Independently onall three continents, people’s social behaviors started to adapt to the requirements of living in settledsocieties that were larger and more complex than those of the hunter-gatherer band. The signature ofsuch social changes may be written in the genome, perhaps in some of the brain genes already knownto be under selection. The MAO-A gene, which influences aggression and antisocial behavior, is onebehavioral gene that, as mentioned in the previous chapter, is known to vary between races and ethnicgroups, and many more will doubtless come to light.

Hard Sweeps and Soft Sweeps

Textbooks about evolution discuss favorable alleles that sweep through a population and becomeuniversal. There are many ancient alleles that have probably become fixed in this way. All humans, atleast compared with chimpanzees, carry the same form of the FOXP2 gene, which is a criticalcontributor to the faculty of speech. A variation called the Duffy null allele has become almostuniversal among Africans because it was an excellent defense against an ancient form of malaria. Agene called DARC (an acronym for Duffy antigen receptor for chemokines) produces a protein thatsits on the surface of red blood cells. Its role is to convey messages from local hormones(chemokines) to the interior of the cell. A species of malarial parasite known as Plasmodium vivax,once endemic in parts of Africa, learned how to use the DARC protein to gain entry into red bloodcells. A mutated version of the DARC gene, the Duffy null allele, then became widespread because itdenies the parasite access to the blood cells in which it feeds and thus provides a highly effectivedefense. Almost everyone in Africa carries the Duffy null allele of DARC, and almost no one outsidedoes.17

Many other mutations have arisen to protect people against current strains of malaria, such asthose that cause sickle-cell anemia and the thalassemias. Sickle-cell anemia occurs with highfrequency in Africa, and beta-thalassemia is common in the Mediterranean, but neither has attainedthe universality of the Duffy null allele within a population. Another widespread but fairly exclusiveallele is associated with skin color. This is an allele of KITLG (an acronym for KIT ligand gene)which leads to lighter skin. Some 86% of Europeans and East Asians carry the skin lightening alleleof KITLG. This allele evolved because of a mutation in the ancestral, skin-darkening version ofKITLG, which is carried by almost all Africans.18 A skin-lightening allele of another gene, calledSLC24A5, has swept almost completely through Europeans.

But the number of such genes, in which one allele has gone to fixation in one race and a differentallele in another, is extremely small and in no way sufficient to account for differences betweenpopulations. Pritchard found no cases of an allele going to fixation among the Yoruba, a large Africantribe in Nigeria. This has led him and other geneticists to conclude that complete sweeps have beenmuch rarer in human evolution than supposed.19

But given that all humans have the same set of genes and that there have been almost no fullsweeps that push different alleles to dominance in different races, how have races come to differ fromone another? The answer that has dawned on geneticists in the past few years is that you don’t alwaysneed a full sweep to change a trait. Many traits, like skin color or height or intelligence, arecontrolled by a large number of different genes, each of which has alleles that individually makesmall contributions to the trait. So if just some of these alleles become a little more common in apopulation, the trait will be significantly affected. This process is called a soft sweep, to contrast itwith a full or hard sweep, in which one allele of a gene displaces all the others in a population.

Pritchard gives the example of height, which is affected by hundreds of genes, because there areso many ways in which height can be increased. Suppose there are 500 such genes and each comes intwo forms, with one allele having no effect on height and the other increasing it by 2 millimeters. Anindividual’s height depends on how many of the height-enhancing alleles he inherits. And that numberin turn is determined by the frequency of each type of allele, meaning how common it is in the

population. So if each of the height-promoting alleles becomes just 10% more common in thepopulation, almost everyone will inherit more of them, and the average person’s height will increaseby 200 millimeters, or 20 centimeters (8 inches).20

This soft sweep process—a small increase in frequency in many genes—is a much easier way fornatural selection to operate than through the hard sweeps—the major jump in frequency of a singleallele—that are often assumed to be the main drivers of evolution. The reason is that the hard sweepsdepend on a mutation creating a novel allele of great advantage, which happens only very rarely in apopulation. In a small population, it may take many generations for such a mutation to occur. Softsweeps, on the other hand, act on alleles that already exist and simply make some of them morecommon. Soft sweeps can thus begin whenever they are needed.

So suppose a group of pygmies were to leave their forest habitat and start herding cattle in a hotclimate, where it’s advantageous to be tall and thin, like the Nuer and Dinka of the Sudan. Thepygmies who were slightly taller would produce more children, and the height-promoting alleles ofthe genes that affect height would immediately begin to become more common in the population. Ineach generation, an individual would have a slightly greater chance of inheriting the height-promotingalleles, and the population would quite quickly become considerably taller.

Consider, on the other hand, a trait in which there is no existing variation, such as the ability todigest milk in adulthood. For most of human existence and still in most people today, the gene forlactase is switched off shortly after weaning. To keep the gene switched on requires a beneficialmutation in the region of promoter DNA that controls it. But the promoter region is some 6,000 DNAunits in length and occupies a minuscule fraction of the 3 billion units of the genome. In a smallpopulation, it might take many generations for the right mutation to occur in so small a target.

Thus it seems to have taken around 2,000 years—some 80 generations—after the start of cattlebreeding for the right mutation in the lactase promoter region to appear among the people of theFunnel Beaker Culture, cattle herders who occupied northern Europe some 6,000 years ago. Onceestablished, the mutation spread rapidly and is now found at high frequency in northern Europe.

Three mutations, which differ from one another and from the European mutation but have the sameeffect, arose independently among pastoralist peoples in eastern Africa and have swept throughroughly 50% of the population. In each case, evidently, evolution has had to wait until the rightmutation occurred, whereupon the allele grew more common because of the great advantage itconferred.

In sum, hard sweeps cannot start until the right mutation occurs, and then they may take manygenerations to sweep through a population. Soft sweeps, based on standing variation in the manygenes that control a single trait, can start immediately. For a species that undergoes a suddenexpansion in its range and needs to adapt quickly to a succession of different challenges, the softsweep is likely to be the dominant mechanism of evolutionary change. This explains why so few hardsweeps are visible in the human genome. Soft sweeps are presumably far more common, though atpresent are very hard to detect. The reason is the difficulty of distinguishing between the minorchanges in allele frequency caused by genetic drift and the also minor changes brought about bynatural selection through a soft sweep.

The Genetic Structure of Race

It is now possible to understand the structure of human variation, at least in broad outline. Differentpopulations don’t have different genes—everyone has the same set. Of the traits specific to one raceor another, a few are encoded in hard sweep alleles that have gone almost to fixation, such as theDuffy null allele or some of the alleles involved in shaping skin color, but many more are probablyencoded in soft sweeps and hence in mere differences in the frequency of the cluster of alleles thatshape each trait.

The fact that genes work in combination explains how there can be so much variation in the humanpopulation and yet so few fixed differences between populations.

Given the importance of allele frequencies in shaping specific traits, it’s not surprising that theyafford a means of identifying an individual’s race. Excluding subjects of a different race is anessential procedure in surveys to detect the alleles that contribute to complex diseases like diabetesand cancer. The idea of these surveys, known as genomewide association studies, is to see if peoplewho are particularly prone to disease are also more likely to carry a particular allele. If so, the allelemay be associated with the disease. But the statistics can be confounded if the population beingsurveyed includes people of more than one race. An apparent association may emerge between thedisease state and a particular allele even though the association is really due to some patientsbelonging to another race, one that naturally has a high frequency of the allele in question.

Medical geneticists have therefore developed sets of test alleles that can be used to distinguishone race from another. Some alleles, particularly those with large differences in frequency betweenraces, are more useful than others. These race-distinguishing DNA sites are known blandly as AIMs,or ancestry informative markers. Using a set of 326 AIMs, researchers achieved a nearly perfectcorrespondence between the race that subjects said they belonged to and the race to which they wereassigned genetically.21 A set of 128 AIMs suffices to assign people to their continental race of origin,whether European, East Asian, American Indian or African.22 (The fifth continental race, Australianaborigines, could doubtless be identified just as easily, but political restrictions have so far largelyblocked the study of aborigine genetics.)

With greater numbers of markers, more closely related groups can be distinguished, such as thevarious ethnicities within Europe.

Some biologists insist that AIMs do not prove the existence of race and that they point instead togeographic origin. But geographic origin correlates very well with race, at least on the continentallevel.

Apart from genetic markers like the Duffy null allele, found almost exclusively in people ofAfrican ancestry, most AIMs are alleles that are just somewhat more common in one race than inanother. A single AIM that occurs in 45% of East Asians and 65% of Europeans says that the carrieris a little more likely to be European, but is hardly definitive. When the results from a string of AIMsare combined, however, an answer with high statistical probability is obtained. This is the samegeneral method used in DNA fingerprinting, except that the 14 sites at which the genome is sampled inforensic DNA analysis are not SNPs but variable runs of DNA repeats.

The approach of comparing allele frequencies can even be used with people of mixed race toassign component parts of an individual’s genome to their parent’s racial origin. When people of

different races marry, their children are perfect blends of their parents’ genes. But at the genetic level,the chunks of DNA that came from the mother’s and the father’s races remain separate anddistinguishable for many generations. Researchers can track along the chromosomes of AfricanAmericans, assigning each stretch of DNA to either African or European ancestors. In one recentstudy, researchers analyzed the genomes of almost 2,000 African Americans and found that 22% oftheir DNA came from European ancestors and the rest from Africans, a conclusion in line withseveral previous reports.23

The same study found evidence that African Americans may already have begun adaptinggenetically to the American environment in the several generations since their ancestors arrived in theUnited States. The malaria-protecting genetic variants common in Africans, such as the variation thatcauses sickle-cell anemia, are no longer a necessity of survival in the United States, so the pressureof natural selection to retain these variants would be relaxed. The authors found some evidence thatthese variants have indeed declined in frequency in African Americans, while genes that provideprotection against influenza have grown more common. The finding, if confirmed, would be a strikinginstance of evolutionary change within the past few hundred years.

Over the last 50,000 years, modern humans have been subjected to enormous evolutionarypressures, in part from the consequences of their own social culture. They explored new ranges andclimates and developed new social structures. Fast adaptation, particularly to new social structures,was required as each population strove to exploit its own ecological niche and to avoid conquest byits neighbors. The genetic mechanism that made possible this rapid evolutionary change was the softsweep, the reshaping of existing traits by quick minor adjustments in the sets of alleles that controlledthem.

But what began as a single experiment with the ancestral human population became a set ofparallel experiments once the ancestral population had spread throughout the world. Theseindependent evolutionary paths led inevitably to the different human populations or races that inhabiteach continent.

Arguments Against the Existence of Race

Readers who are by now persuaded that recent human evolution has resulted in the existence of racesmay wish to proceed to the next chapter. But for those who remain perplexed that so many socialscientists and others should argue race does not exist, here is an analysis of some of their contentions.

Start with Jared Diamond, the geographer and author of Guns, Germs, and Steel, who was quotedin chapter 4 as comparing the idea of race with the belief that the Earth is flat. His principal argumentfor the nonexistence of race is that there are many different “equally valid procedures” for defininghuman races, but since all are incompatible, all are equally absurd. One such procedure, Diamondproposes, would be to put Italians, Greeks and Nigerians in one race, and Swedes and Xhosas (asouthern African tribe) in another.

His rationale is that members of the first group carry genes that confer resistance to malaria andthose of the second do not. This is just as good a criterion as skin color, the usual way of classifyingraces, Diamond says, but since the two methods lead to contradictory results, all racial classificationof humans is impossible.

The first flaw in the argument is the implied premise that people are conventionally assigned toraces by the single criterion of skin color. In fact, skin color varies widely within continents. InEurope it runs from light-skinned Swedes to the olive complexion of southern Italians. Skin color isthus an ambiguous marker of race. People belong to a race not by virtue of any single trait but by acluster of criteria that includes the color of skin and hair, and the shape of eyes, nose and skull. It isnot necessary for all these criteria to be present: some East Asians, as noted above, lack the EDARallele for thick hair, but they are still East Asians.

The single criterion that Diamond proposes as an alternative, genes that confer resistance tomalaria, makes no evolutionary sense. Malaria became a significant human disease only veryrecently, some 6,000 years ago, and each race then independently developed resistance to it. Italiansand Greeks resist malaria because of mutations that also cause the blood disease known asthalassemia, whereas Africans resist malaria through a different mutation that causes sickle-cellanemia. The trait of resisting malaria is one that has been acquired secondarily to race, so obviouslyit is not an appropriate way of classifying the populations. A scholar’s duty is to clarify, butDiamond’s argument seems designed to distract and confuse.

A more serious and influential argument, also designed to banish race from the political andscientific vocabulary, is one first advanced by the population geneticist Richard Lewontin in 1972.Lewontin measured a property of 17 proteins from people of various different races and calculated ameasure of variation known as Wright’s fixation index. The index is designed to measure how muchof the variation in a population resides in the population as a whole and how much is due todifferences between specific subpopulations.

Lewontin’s answer came out to 6.3%, meaning that of all the variations in the 17 kinds of proteinhe had looked at, only 6.3% lay between races, while a further 8.3% lay between ethnic groupswithin races. These two sources of variation add up to around 15%, leaving the rest as common to thepopulation as a whole. “Of all human variation, 85% is between individual people within a nation ortribe,” Lewontin stated. He concluded on this basis that “human races and individuals are remarkablysimilar to each other, with the largest part by far of human variation being accounted for by the

differences between individuals.”He went on to say that “Human racial classification is of no social value and is positively

destructive of social and human relations. Since such racial classification is now seen to be ofvirtually no genetic or taxonomic significance either, no justification can be offered for itscontinuance.” 24

Lewontin’s thesis immediately became the central genetic plank of those who believe that denyingthe existence of race is an effective way to combat racism. It is prominently cited in Man’s MostDangerous Myth: The Fallacy of Race, an influential book written by the anthropologist AshleyMontagu with the aim of eliminating race from the political and scientific vocabulary. Lewontin’sstatement is quoted at the beginning of the American Anthropological Association’s statement on raceand is a founding principle of the assertion by sociologists that race is a social construct, not abiological one.

But despite all the weight that continues to be placed on it, Lewontin’s statement is incorrect. It’snot the basic finding that is wrong. Many other studies have confirmed that roughly 85% of humanvariation is among individuals and 15% between populations. This is just what would be expected,given that each race has inherited its genetic patrimony from the same ancestral population thatexisted in the comparatively recent past.

What is in error is Lewontin’s assertion that the amount of variation between populations is sosmall as to be negligible. In fact it’s quite significant. Sewall Wright, an eminent populationgeneticist, said that a fixation index of 5% to 15% indicates “moderate genetic differentiation” andthat even with an index of 5% or less, “differentiation is by no means negligible.” 25 If differences of10 to 15% were seen in any other than the human species they would be called subspecies, inWright’s view.26

Why should Wright’s judgment that a fixation index of 15% between races is significant bepreferred over Lewontin’s assertion that it is negligible? Three reasons: (1) Wright was one of thethree founders of population genetics, the relevant discipline; (2) Wright invented the fixation index,which is named after him; (3) Wright, unlike Lewontin, had no political stake in the issue.

Lewontin’s argument has other problems, including a subtle error of statistical reasoning namedLewontin’s fallacy.27 The fallacy is to assume that the genetic differences between populations areuncorrelated with one another; if they are correlated, they become much more significant. As thegeneticist A.W.F. Edwards wrote, “Most of the information that distinguishes populations is hidden inthe correlation structure of the data.” The 15% genetic difference between races, in other words, isnot random noise but contains information about how individuals are more closely related tomembers of the same race than those of other races. This information is brought to light by the clusteranalyses, described earlier in this chapter, which group people into populations that correspond at thehighest level to the major races.

Despite the misleading political twist on Lewontin’s argument, it became the centerpiece of theview that racial differences were too slight to be worth scientific attention. The assertion left the uglyimplication that anyone who thought otherwise must be some kind of a racist. The subject of humanrace soon became too daunting for all but the most courageous and academically secure ofresearchers to touch.

A frequent assertion of those who seek to airbrush race out of human variation is that no distinctboundaries can be drawn between one race and another, leaving the implication that races cannot

exist. “Humanity cannot be classified into discrete geographic categories with absolute boundaries,”proclaims the American Association of Physical Anthropologists in its statement on race.28 True,races are not discrete entities and have no absolute boundaries, as already discussed, but that doesn’tmean they don’t exist. The classification of humans into five continental based races is perfectlyreasonable and is supported by genome clustering studies. In addition, classification into the threemajor races of African, East Asian and European is supported by the physical anthropology of humanskull types and dentition.

A variation on the no distinct boundary argument is the objection that the features deemeddistinctive of a particular race, like dark skin or hair type, are often inherited independently andappear in various combinations. “These facts render any attempt to establish lines of division amongbiological populations both arbitrary and subjective,” states the American AnthropologicalAssociation’s statement on race.29 But as already noted, races are identified by clusters of traits, andto belong to a certain race, it’s not necessary to possess all of the identifying traits. To take apractical example of what the anthropologists are talking about, most East Asians have the sinodontform of dentition, but not all do. Most have the EDAR-V370A allele of the EDAR gene, but not alldo. Most have the dry earwax allele of the ABCC11 gene, but all not all do. Nonetheless, East Asianis a perfectly valid racial category, and most people in East Asia can be assigned to it.

Even when it is not immediately obvious what race a person belongs to from bodily appearance,as may often be the case with people of mixed-race ancestry, race can nonetheless be distinguished atthe genomic level. With the help of ancestry informative markers, as noted above, an individual canbe assigned with high confidence to the appropriate continent of origin. If of admixed race, like manyAfrican Americans, each block of the genome can be assigned to forebears of African or Europeanancestry. At least at the level of continental populations, races can be distinguished genetically, andthis is sufficient to establish that they exist.

C

6

SOCIETIES AND INSTITUTIONS

It is not yet common practice to link the current social and national habitus of a nation to its so-called“history,” and especially to the state-formation process it has experienced. Many people seem to have theunspoken opinion that “What happened in the twelfth, fifteenth or eighteenth centuries is past—what has it todo with me?” In reality, though, the contemporary problems of a group are crucially influenced by their earlierfortunes, by their beginningless development.

—NORBERT ELIAS1

hinese society differs profoundly from European society, and both are entirely unlike atribal African society. How can three societies differ so greatly when their members,beneath all the differences of dress and skin color, resemble one another so closely interms of the set of behaviors that comprise human nature? The reason is that the three

societies differ greatly in their institutions, the organized patterns of behavior that structure a society,equip it to survive in its environment and enable it to compete with neighboring groups.

The institutions of Chinese, European and African societies have been deeply shaped by theirrespective histories as each responded to the specific challenges of its environment. The historicaldevelopments that shaped some of these institutions are described below. But it must first be notedthat a society’s institutions, despite their rich cultural content, are not autonomous; rather, they arerooted in basic human social behaviors. These social behaviors, as described in chapter 3, lie at thefoundation of human existence as a social species. They include an instinct to cooperate vigorouslywith members of an in-group, to obey the in-group’s rules and to punish those who deviate. There isan instinct for fairness and reciprocity, at least among members of the group. People have an intuitivemorality, which is the source of instinctive knowledge that certain actions are right or wrong. Peoplewill fight to the death to protect their own group or attack that of others. Probably all these socialbehaviors, to one degree or another, have a genetic basis although, with the few exceptions alreadydescribed, the specific underlying genes have yet to be identified.

Social institutions are a blend of genetics and culture. Each major institution is based ongenetically influenced behaviors, the expression of which is shaped by culture. The human instinctsfor exchange and reciprocity probably undergird much of economic behavior but obviously theexpressions of it, from farmers’ markets to synthetic collateralized debt obligations, are cultural.“The innate mental capacities of humans underlie personal exchange. These genetic features providethe framework for exchange and are the foundation of the structure of human interaction thatcharacterizes societies throughout history,” writes the economist Douglass North, an authority oninstitutions.2 The exact mix of genetic predispositions and culture in institutions has yet to be

resolved, he notes.Warfare, religion, trade and law are social institutions found throughout the world. Warfare is

based on the deep-seated instinct to protect one’s family and group, as well as on predatory motives,such as stealing the women or property of others. The instinct for religious behavior, found in everysociety, was essential for group cohesion among early human communities and continues to play aleading role in modern societies, even though other institutions have assumed many of its formerroles. Trade, as noted, is founded on the human instincts for exchange and reciprocity. Law is rootedin several complex social instincts, including those for following rules, punishing violators of socialnorms and the sense of personal transgression that underlies self-punishment and shame.

Without knowing the nature of the genes involved in social behavior, it’s impossible at present todisentangle the respective roles of culture and genetics in shaping social institutions. But languagemay provide a relevant example. The rules of grammar are so complex that it’s hard to think everyinfant learns them from scratch. Rather, there must be neural machinery that both generates rules ofgrammar and predisposes children to learn whatever language they hear spoken around them. The roleof the genes is to set up this neural learning machine. But culture provides the entire content oflanguage.

It is notable that the cultural component of language changes surprisingly quickly: the English of700 years ago is barely comprehensible today. The genetic machinery has presumably stayed ratherconstant, given that the fundamental nature of language seems the same around the world.

A similar fusion of genetics and culture is probably present in religion. The fact that every knownsociety has a religion suggests that each inherited a propensity for religion from the ancestral humanpopulation. The alternative explanation, that each society independently invented and maintained thisdistinctive human behavior, seems less likely. The propensity for religion seems instinctual, ratherthan purely cultural, because it is so deeply set in the human mind, touching the emotional centers andappearing with such spontaneity. There is a strong evolutionary reason, moreover, that explains whyreligion may have become wired into the neural circuitry. A major function of religion is to providesocial cohesion, a matter of particular importance among early societies. If the more cohesivesocieties regularly prevailed over the less cohesive, as would be likely in any military dispute, aninstinct for religious behavior would have been strongly favored by natural selection. This wouldexplain why the religious instinct is universal. But the particular form that religion takes in eachsociety depends on culture, just as is the case with language.

The surprising longevity of many social institutions is commonly attributed to culture alone.Despite the malleability of culture and its ephemeral shifts under the influence of fashion, somecultural forms can persist for many generations and the material aspects of culture can be immenselystable—the spear has been around for millennia. But it’s just as likely that in social institutions thatare a blend of culture and genetics, it is the genetic component that provides the stability. Geneticallybased social behavior takes many generations to change whereas culture tends to drift. Even in caseswhere stability would seem to confer great benefit, culture can shift quite dramatically in just a fewcenturies. Despite the advantage of constancy in communication, languages change every generation.Religions too depend strongly on the appearance of constancy and antiquity, yet their cultural formschange quite rapidly, as is seen in the shifting shapes of Protestantism in the United States; thePuritans gave way to Congregationalism which was succeeded by Methodism, which peaked around1850 and was overtaken by the Baptists.

The genetically based social behaviors that undergird institutions can, like any other hereditarytrait, be modulated by natural selection. Human social nature is much the same from one society toanother, but slight variations in social behaviors can probably generate significant and long enduringdifferences in a society’s institutions. A small difference in the radius of trust may underlie much ofthe difference between tribal and modern societies. The genetic basis of this behavior is unknown andso cannot be measured. But races and ethnicities are known to differ, for instance, in the structure ofthe MAO-A gene that controls aggression, as noted in chapter 3, and the differences in this gene mayhave been shaped by natural selection.

Institutional continuity that extends over many centuries, and over millennia in the case of China,may thus reflect the stability provided by the institutions’ genetic components. One indication of sucha genetic effect is that, if institutions were purely cultural, it should be easy to transfer an institutionfrom one society to another. But American institutions do not transplant so easily to tribal societieslike Iraq or Afghanistan. Conversely, the institutions of a tribal society would not work in the UnitedStates—indeed, many of them would be illegal—even if Americans could figure out what tribe theybelonged to. Afghans, in order to survive in conditions where central government is usually weak,have had to rely on tribal systems for protection over the centuries, and tribal institutions requirebehaviors—like blood revenge and the killing of female relatives deemed to have dishonored thetribe—which differ from those that are successful in, for instance, Scandinavian democracies.

The Great Transition

Perhaps the most dramatic example of a human society adapting through institutional change is thetransition from nomadic hunter-gatherer societies to settled groups, which started only 15,000 yearsago. The new institutions of settled society required a thorough makeover of human social behavior.That may explain in part why it took modern humans so long to accomplish what might seem anobviously desirable goal, that of settling in one place instead of roaming about and owning only whatcould be carried.

The great transition to settled life was not a single event. The ancestral human population wasalready dispersed across the globe when the transition started to occur. In each continent, thenecessary behavioral changes occurred independently and took many generations to spread to almosteveryone. Just as the populations of Europe and East Asia acquired pale skin through different geneticmechanisms, so too they independently developed the new social behaviors required to adopt asettled mode of existence. The seeds of difference between the world’s great civilizations wereperhaps present from the first settlements.

The institutions of hunter-gatherer societies differed greatly from those of the settled societiesthey became. Hunter-gatherer bands, to judge by the behavior of living hunter-gatherers, consisted ofjust 50 to 150 people; when they grew larger, quarrels would break out and lead to division, usuallyalong kinship lines.

Within the hunter-gatherer groups, there were no headmen or chiefs. Strict egalitarianismprevailed and was enforced. Anyone who tried to boss others about was firmly discouraged and, ifthat failed, killed or ostracized. Most hunter-gatherers have no property apart from the few personalbelongings that can be carried. Their economies are therefore rudimentary and do not play a majorpart in their survival.

Genetically, hunter-gatherer systems probably gain stability from the fact that variance issuppressed by egalitarianism. Individuals with exceptional qualities, such as great intelligence orhunting skill, cannot take direct advantage of such talents to have more children because of rules thatrequire a catch to be shared with others. The social behavior of hunter-gatherer groups thus had noparticularly strong driving force toward change.

What made settlement desirable, despite the risks, was population pressure. Hunter-gatherersrequire a large amount of land to provide the plants and animals they consume. After a time, evenwith high mortality due to incessant warfare, the available land started to run out. There was littlechoice but to make more intensive use of existing resources, for instance by gathering and plantingwild grass seed and by controlling and penning wild animals. These practices eventually led, as muchby accident as by design, to the invention of agriculture some 10,000 years ago.

The first settlements induced profound changes in human social behavior. Hierarchical systemswere essential for organizing the larger numbers of people in settled communities. The egalitarianismof hunter-gatherers was abandoned. People learned the unaccustomed skills of obeying a boss. Theirmental world too was transformed. The settled communities accumulated surpluses for the first time,and these could be traded. The management of these surpluses required a new kind of skill, and theirdefense entailed new forms of military organization.

In hunter-gatherer societies, the only division of labor was between the sexes: the men hunted and

the women gathered. In settled societies, there was specialization of labor. In the wake of thespecialization followed disparities of wealth.

The social and genetic variance of the society was greatly increased by these changes. A personwith social skills and intelligence had a reasonable chance of getting richer, something that wasseldom possible in a hunter-gatherer society, where there were no disparities and no wealth to speakof. Inequality in place of egalitarianism may not seem a good exchange, but the switch was essentialfor the new social structures required to operate large settled societies.

The elites that emerged in the first settled societies were able to raise more surviving children.They developed a keen interest in passing on their advantages of wealth and rank. But if the rich havemore children and the population remains the same size, some children of the rich must descend insocial rank. The social behaviors of the elites could thus trickle down genetically into the rest ofsociety. The ability of the rich to produce more surviving children created for the first time apowerful mechanism whereby natural selection could enhance successful behaviors. In societieswhere aggression paid, aggressive men would have more children. In those in which conciliation ortrading abilities carried a payoff, people with these traits would leave the larger imprint on the nextgeneration.

The rapid adoption of new social behaviors was required for reasons both internal and externalto the new societies. Within each society, people needed a very different set of skills as they adaptedto new institutions like specialization of labor. And the society itself had to adapt to externalpressures, such as extracting resources from a changing environment and surviving in battle againstother groups. Consider how radically two critical institutions, warfare and religion, changed in natureduring the transition to settlement.

Warfare is an institution doubtless inherited from the joint ancestor of chimps and humans, giventhat both species practice territorial-based aggression. To judge from the behavior of living hunter-gatherer societies, harsh initiation rites at puberty taught young men to bear pain without flinching.Because members of a hunter-gatherer band or tribe are usually quite highly related to one another,kinship was a strong element of group cohesion. In settled societies, kinship was abandoned as anessential basis of military cohesion once population grew beyond a certain size. Leaders tookadvantage of the fact that men who had become habituated to hierarchy in daily life were willing toaccept military discipline.

Religion too underwent a thorough makeover in settled societies. In hunter-gatherer groups,religion is often centered around communal dances. The dances are long and vigorous and extend farinto the night. There is something about rhythmic movement in unison that instills a sense of belongingto a group. There are no priests among hunter-gatherers; everyone in the group is an equal celebrant.People communicate with their gods directly, usually when some members of the group go into atrance induced by the dancing itself or by drugs.

In settled societies, by contrast, religious officials emerged as intermediaries between the peopleand their gods. The dancing was repressed: it represented a threat to religious authority since itallowed people to communicate with their gods directly instead of depending on the priests’interpretations. Knowledge of the gods no longer resided in songs and verbal tradition; it wasassembled in religious doctrines expounded by the priests.

Religion in early societies assumed a central structural role, with the ruler often appointinghimself chief priest. The pharaoh of ancient Egypt was chief priest; Roman emperors often took the

title of pontifex maximus. In early settled societies that lacked any formal system of justice or theapparatus of police and courts, religion and fear of the gods’ displeasure were essential means ofmaintaining order.3

People responded for the most part in cultural ways to the changing nature of institutions likewarfare and religion. But both behaviors probably have an instinctual or genetic basis that can beadapted over the generations, just like any other form of behavior. In a tribal society, such as theYanomamö of Venezuela and Brazil, aggressive men are valued as defenders in the incessant warfarebetween villages, and those who have killed in battle—the unokais—have on average 2.5 morechildren than men who have not killed, according to the anthropologist Napoleon Chagnon.4 In otherkinds of society, however, highly aggressive people are unlikely to prosper and will on balance havefewer children; the genetic predisposition for aggression will therefore fade over the generations,which is probably one reason why modern societies are less violent than those of medieval andearlier times.

Human social behaviors, from aggression to empathy, shape the institutions of each society,although all the details are supplied by culture. Since these institutions must change as a society’secological and military situation changes, every aspect of human social behavior is under constantpressure from natural selection. The great transition from hunting and gathering to settled lifesubjected human social nature to one set of pressures. Then began another remolding process, equallyextensive—that of transforming the new villagers into the subjects of empires.

From Village to Empire

Social anthropologists usually take care not to imply that human societies have evolved, lest it seemthat those that are further evolved are more advanced than others and hence superior to them. Butthere does seem to have been extensive evolution in human social behavior in forming civilizationssuch as those of ancient Egypt, Mesopotamia and China. All seem to have evolved through the samesequence of steps, or at least along parallel paths, when confronted with the same challenge.

A driving force in all these cases was demography. After the first settlements, populations startedto grow. The first settlers lived in villages of perhaps 150 people. Villages would then start tocooperate, both for large agricultural projects and for defense. The larger numbers of people living inthese local groups then had to be organized in some way, and this requirement led to hierarchicalsocieties led by a chief. Warfare exerted a selective pressure under which the more cohesivesocieties destroyed or absorbed those that were less well organized. There was a dramatic change inhuman social nature that underlay a vast change in the maximum size of human societies. Hunter-gatherer groups tend to split in two when they have more than 150 or so members; by the time of thefirst urban civilizations that started to arise some 5,000 years ago, people were living in cities withpopulations of 10,000 to 100,000.

The first chiefs secured their political power by also holding religious office. They ran theirchiefdoms as family affairs, with their relatives forming a hereditary elite. But a group of chiefdomswas not a stable situation, especially if they occupied a region whose agricultural resources werecircumscribed by mountains or deserts. Because of such geographical limits, the chiefdoms wouldimpinge on one another if any tried to expand. These conditions made warfare almost inevitable.

Within each region of the world, it was war between chiefdoms that led to the emergence of thefirst anarchic states. “Historical or archaeological evidence of war is found in the early stages ofstate formations in Mesopotamia, Egypt, India, China, Japan, Greece, Rome, northern Europe, centralAfrica, Polynesia, Middle America, Peru and Columbia, to name only the most prominent examples,”writes the anthropologist Robert Carneiro.5

Chiefdoms generally fought one another for territory, killing or expelling those whose lands theytook over. But at a certain scale of operations, when the population was dense enough and sufficientlyproductive to support a ruling class, the larger chiefdoms developed into states. The states fought notjust for land but also for population; instead of driving conquered people off their territory, an empirewould subjugate them as part of the state’s manpower.

Growing too large and complex to be managed by the ruler’s family, the states developed theirown cadre of officials. War between rival chiefdoms in a region could be a sanguinary affair. Butonce a single ruler had unified a region, there was a much greater degree of stability and order.

A general pattern in world history is that states first developed in regions of high populationdensity, particularly along the banks of major rivers where irrigated agriculture was easy. The ancientEgyptian state began at around 3100 BC when Narmer, the ruler of the southern chiefdom of the Nile,defeated the northern chiefdom and created a unified system.

The Sumerian civilization developed around the same time along the Euphrates River in theregion that is now Iraq. In India the Harappan civilization emerged in the Indus River valley. TheChinese state was built by consolidation of the settlements that arose along the Yellow River and

Yangtze River valleys.All these first generation states began to emerge some 5,000 years ago in the Old World. The

process was much delayed in the New World because the population pressure necessary for statedevelopment did not begin until long after 15,000 years ago, when the first inhabitants crossed fromSiberia to Alaska via Beringia, the now sunken land bridge that connected the two continents. InMesoamerica, the Olmec state started to flourish around 1500 BC. In South America, the Moche statebegan around 100 AD, and the Inca empire, the most advanced state of South America, did not emergeuntil the 12th century AD.

The tight historical relationship between state formation and population size is evident whenlooking at the less easily habitable regions of the world. There are no states in the Arctic regions,sparsely inhabited by the Eskimo people. In Polynesia, there are only chiefdoms, probably becausethe carrying capacity of most islands permits only small populations. A major exception is Hawaii,but King Kamehameha did not unite the islands until 1811 AD.

A major region of slow population growth was Africa south of the Sahara. The continent suffersfrom a lack of navigable rivers, and disease makes many regions hard to inhabit. Some of Africa’schiefdoms had grown into large kingdoms, such as the Ashanti empire in Ghana, the Ethiopian empire,and the Shona kingdom in Zimbabwe by the time Europeans arrived and thwarted their furtherdevelopment. In 1879 a Zulu army armed with spears and oxhide shields defeated a British forcearmed with modern weapons at the battle of Isandlwana. But throughout much of Africa, the lack ofdense populations and large scale warfare, two essential ingredients in the formation of modernstates, prevented such structures from arising. Africa south of the Sahara remained largely tribalthroughout the historical period, as did Australia, Polynesia and the circumpolar regions.

The evolution of human social behavior was thus different and largely or entirely independent oneach continent. States had developed in the Middle East, in India and in China by around 5,000 yearsago, and in Central and South America by about 1,000 years ago. For lack of good soils, favorableclimate, navigable rivers and population pressure, Africa remained a continent of chiefdoms andincipient empires. In Australia, people reached the tribal level but without developing agriculture;their technology remained that of the Stone Age into modern times.

Human Behavior in History

Although historians usually focus on states and how the actors within them seize the levers of power,in the long term it is institutions that are more important determinants of a society’s fate. Being builton ingrained social behavior, institutions may endure for generations and resist even the mostcatastrophic events. Russians were still Russians after Stalin, Chinese remained Chinese under MaoTse-tung; even Hitler was largely an aberration in German history.

History has little coherence when analyzed in terms of individuals or even nations. But when seenin terms of the institutions developed by different civilizations and races, the outline of a logicaldevelopment emerges. Though there is still a large random element, the broad general theme of humanhistory is that each race has developed the institutions appropriate to secure survival in its particularenvironment. This, then, is the most significant feature of human races: not that their members differ inphysical appearance but that their society’s institutions differ because of slight differences in socialbehavior.

A landmark analysis of human history in terms of social institutions has recently been written bythe political scientist Francis Fukuyama. His thesis, describing how each of the major civilizationsadapted its institutions to its local geography and historical circumstances, provides a roadmap ofhuman social adaptation and the different paths taken by each civilization.

Fukuyama’s premise, like that of North quoted above, is that institutions are rooted in humansocial behavior. “The recovery of human nature by modern biology . . . is extremely important as afoundation for any theory of political development, because it provides us with the basic buildingblocks by which we can understand the later evolution of human institutions,” he writes.6

A pillar of human social nature is the tendency to favor family and close kin, and this is the rootof tribalism. Tribal societies were the first form of human political organization, given that the hunter-gatherer bands in which humans have passed most of their existence were probably organized astribes from an early date. A tribe consisted of bands that exchanged women in marriage. Tribalorganization is highly flexible, and tribes can grow to vast sizes capable of considerableundertakings: the Mongols, whose empire stretched from the Pacific Ocean to the borders of Europe,were tribally organized. The weak point of the tribal system is succession: when a strong leader dies,the chiefs of the component lineages tend to fight one another to succeed him, and the whole coalitionmay break down into smaller, feuding entities, as was the fate of the Mongol empire.

Tribes are organized on the basis of lineages traced through the male line of descent. Within atribe, two lineages may fight each other or join together to vie with a third. Because all lineagesdescend from a founding patriarch, any two lineages can find a joint ancestor to prove their kinshipand affinity as allies. Anthropologists call tribes segmentary societies because of the way in whichthe different lineages or segments can be fitted together for particular social purposes.

The tribal system is so strong, in Fukuyama’s view, that even in most modern states it never fullydisappears. Rather, the state apparatus is layered on top and is in constant tension with it. In China,officials use their positions to advance their kindreds’ interests, regardless of the state’s. Theproblem is as pertinent in China today as at any point in the past. Even in Europe and the UnitedStates, where family relationships are less intricate and tribes no longer exist, nepotism is far fromunknown.

Tribalism is the default state of early human societies, just as autocracy is the default state ofmodern ones. Tribal societies have existed probably from the beginning of the human species, andmany still exist in the present day. The inhabitants of Spain, France, Germany and England were tribalpeoples before and after their conquest by the Roman state. In China, tribal chiefdoms did not start todisappear until the 4th century BC; in much of Africa and the Middle East, tribal organization remainsa potent force.

Given the pervasiveness of tribalism, how did modern states ever get started? Fukuyama’sapproach to the answer is to consider the differences between modern states in order to understandwhich of their features are the most significant. Surveying the modern states that arose in China,Europe, India and the Muslim world, he finds that all had to confront the same principal challenge,that of suppressing tribalism so that the state’s authority could prevail, but that each accomplished thisgoal in very different ways.

China achieved a modern state a millennium before Europe. This precocious advance may havehad a lot to do with the nature of the plain between the Yangtze and Yellow rivers. The territory iswell suited both for agriculture, which leads to population growth, and for warfare, the two principalpropellants of state formation. A relentless process of consolidation forced tribal systems to yield tostates.

In 2000 BC, a large number of political entities—traditionally put at 10,000—existed in theYellow River valley. By the time of the Shang dynasty in 1500 BC, these had dwindled to some 3,000tribal chiefdoms. The Eastern Zhou dynasty began in 771 BC with 1,800 chiefdoms and ended with 14entities that were much closer to states. During the ensuing Warring States period, which lasted fromaround 475 BC to 221 BC, the 7 remaining states were reduced to 1.

China became unified in 221 BC when the state of Qin managed to defeat its six rivals during theWarring States period. This was the culmination of some 1,800 years of almost incessant strife,during which the demands of warfare shaped the distinctive lineaments of the Chinese state.

The tribal system endured as long as the Yellow River valley was relatively uninhabited. Aweaker tribe could just move elsewhere. As population density increased, the choice became to fightor to be extinguished.

The pressure on the tribes arose through their mode of fighting. Being based on male lineages, thefighting was done by nobles in chariots, with each chariot requiring a logistics train of some 70soldiers. With incessant wars, the number of available nobles was eventually depleted. Indesperation, some chiefdoms during the Zhou period developed an alternative mode of warfare, thatof impressing the peasantry into infantry armies.

This was not a simple transformation, given that it did not recommend itself to either the nobilityor the peasantry. Moreover, it required a complex and imaginative set of institutional changes. Largerarmies required raising more taxes to support them. Extracting taxes from the population madenecessary a class of officials loyal to the state, not to particular tribes.

These changes began in several states, but it was in Qin, the most westerly of the seven warringstates, that the reforms were pushed furthest. “Groundwork for the first truly modern state was laid inthe western polity of Qin under Duke Xiao and his minister Shang Yang,” Fukuyama writes.7

The Qin leaders built a modern state because they recognized explicitly that the noble lineages ofthe tribal system were an impediment to the state’s power. Shang Yang abolished the hereditaryoffices held by the nobles in favor of a 20 rank system based on military merit. This change meant that

all officeholders now owed their position and loyalty to the state, not to their tribe or lineage.Not only was the bureaucracy appointed on merit, it was also rewarded on performance.

Important items such as land, servants, concubines and clothing were distributed to those who servedthe state well.

In a second bold stroke of social engineering, Shang Yang let peasants own land directly insteadof having to work fields owned by the nobility. The peasants were now directly beholden to the stateand owed their taxes to the state, not the nobility.

But this was no agricultural reform designed for the peasants’ benefit. Previously the peasants hadworked under the nobles’ supervision. Shang Yang had them reorganized into groups of five or tenhouseholds, which were required to supervise one another and report crimes to the state. Failure toreport was punishable by death.

“If the people are stronger than the government, the state is weak; if the government is strongerthan the people, the army is strong,” states the treatise attributed to Shang Yang.8 This was the point ofthe whole exercise. The peasantry was controlled and taxed. The bureaucrats administered the stateand raised the taxes to finance a mass peasant army.

The westerly Qin state, though long regarded as something of a backwater, now had the politicalorganization required to pay for a substantial army. With this force, the Qin king was able in 221 BCto defeat his six rivals and unify China. Unification brought to an end the deadly game of the 254-yearWarring States period, during which 468 wars were fought between the rival players.

The Chinese had invented the modern state more than a thousand years before Europe did. Afinishing touch was added when the Mandarin examination system was instituted in 124 BC underemperor Wu. Besides an army, tax collection systems, registration of the population and draconianpunishments, China had another institution, one that the sociologist Max Weber considered thedefining mark of a modern state, that of an impersonal bureaucracy chosen by merit.

The Chinese state arose because tribal organization could not handle the demands of the Chinesestyle of warfare. With China as a template, comparisons can be made with how other civilizationsdeveloped modern states. Europe, for instance, after the disintegration of the Roman empire, had aperiod analogous to the Eastern Zhou dynasty when its tribes were developing into states, symbolizedby the process in which the king of the Franks became instead the king of France. During this period,the number of European polities was reduced from about 500 to 25. But Europe then deviated fromthe Chinese pattern, because this process of reduction was not followed by a final unification, aWarring States epoch in which one state emerged the winner.

Why did no counterpart of the state of Qin arise to conquer all of Europe? One reason may be thatstate building came a thousand years later to Europe, by which time feudalism had secured a strongerfoothold than in China. The local chieftains could not be dispossessed in the Shang Yang style. Kingshad to negotiate with them. So no European state became strong enough to dominate all the others inany sustained way; after the Romans, attempts at empire in Europe were always partial and short-lived.

Another reason is that barriers of geography and culture were more formidable in Europe than inthe Yellow River valley. Europe is divided by mountain ranges and rivers, and within these naturalcompartments emerged differences of religion and language. These impediments made it far harder toconstruct a unified European state.

China was able to develop the institutions of an autocratic state, ones so effective that China for

most of its modern history has been unified, though punctuated by short, disruptive periods ofdisunity. Despite its autocratic nature, the state was several times conquered by one or another of thevarious tribal pastoralists, like the Mongols or the Manchu, who roamed the steppes beyond China’snorthern border. Yet these conquerors found that to rule China they had to abandon their tribal waysand adopt Chinese institutions.

A striking counterpoint to the Chinese pattern of development is provided by India. By the 6thcentury BC, the first states had developed in India, as in China. But whereas in China there followed500 years of incessant warfare, India did not undergo such a process, perhaps because populationwas less dense. The principal shaper of Indian society was not war but religion. Brahmanism dividedsociety into four classes, those of priests, warriors, merchants and everyone else. The four classeswere subdivided into hundreds of endogamous occupational castes. This system, layered on top of thetribal divisions, proved so strong that no government could overrule it. India thus created a strongsociety and a weak state, the inverse of the Chinese situation in which, then as now, the people haveseldom challenged the state-controlled institutions.

The state was so weak, in fact, that it has seldom been unified. The Maurya empire ruled all butsouthern India for a century after 321 BC but, unlike the Qin in China, did not seek to impose its owninstitutions throughout the empire. When it disintegrated, it was only foreign invaders who showed aninterest in integrating the subcontinent, such as the Mughals and then the British.

There is no basis in Indian political institutions for a tyrannical state, whereas in China since theQin, the state has always assumed the right to tell its citizens what to do. Yet China, for all itsprecocious modernity, never developed the rule of law, the concept that the ruler should be subject tosome independent body of rules. In India, Fukuyama writes, law “did not spring from politicalauthority as it did in China; it came from a source independent of and superior to the political ruler.”

India did not develop the formal mechanisms contrived by European states for holding the ruleraccountable to the law. But from the earliest times, the religious law was a central institution thatcircumscribed the power of the state. The respective institutions developed by India and China had amajor role in shaping their different histories up until the present day. From the Great Wall to theThree Gorges Dam, the Chinese state has never hesitated to force costly public works on its citizens,who have no way to object or resist. In India, by contrast, the government cannot propose a newairport or factory site without facing vociferous public protest.

In China, tribalism was suppressed by direct actions of the state; in India, by religion. The mostinventive way of undermining tribalism was developed in the Islamic world by the Abbasid dynastyand brought to perfection by the Ottomans. This was the institution of military slavery, in which boththe military and the bureaucratic elite of the empire were made up of slaves. A matter of possibleenvy to any chief executive who has tried to impose his wishes on a resistant bureaucracy, the sultancould order the execution of any slave bureaucrat, from those of the lowest ranks up to the grandvizier. The slaves, at least in principle, were forbidden to have families or, if allowed to marry, theirsons were prohibited from becoming soldiers or succeeding their fathers in office.

The strong human instinct of favoring one’s family or kin was thus thwarted. The elite slaveofficeholders were the empire’s aristocracy for just a generation; their children had to join thegeneral population. As for the problem of where to acquire the slaves (Islam forbids the enslavementof Muslims), the Ottomans addressed that with the devshirme, a system in which talent spotters wouldvisit Christian provinces, notably Serbia, and require local priests to provide a register of all boys

baptized in the region. The most promising were abducted from their parents, whom they would neversee again. They were then converted to Islam and trained either to become senior administrators or tojoin the Janissaries, an elite military group.

As bizarre and inhuman as the institution of military slavery may seem, it shows the lengths towhich a state would go in order to thwart tribalism and secure a caste of administrators responsive tothe ruler’s commands. The institution was invented by the Abbasids, the Islamic dynasty that heldsway in the Near East from 750 to 1258 AD, but they found it impossible to rule a far-flung empirewith Arab tribal organization. It was further developed by the Ayyubid Sultans of Egypt, who createdan army, the Mamluks, from slaves captured from Turkic tribes and the Caucasus. In slave armieswith no nobility or kinship system, people could be promoted purely on merit. This and thecommanders’ exclusive loyalty to their sultan were key to the success of the Mamluk and Janissaryarmies.

The Mamluks of Egypt saved the Islamic world by defeating an invading Mongol army in 1260 atthe battle of ‘Ain Jalut. But the commander of the Mamluk army, Baibars, then overthrew his masterand became sultan of Egypt. The Mamluks continued to be a formidable military force for severaldecades, defeating three more Mongol invasions. But wealthy Mamluks then found ways to defeat theprohibition on bequeathing wealth to their descendants, and the system gradually retribalized itself.“The one-generation nobility principle worked against the basic imperatives of human biology, just asthe impersonal Chinese examination system did,” Fukuyama observes. “Each Mamluk sought toprotect the social position of his family and descendants.”

The Mamluk system started to decay. Ridden by factionalism and handicapped by their disdainfor the new firearms now dominating battlefields, the Mamluks were defeated by the Ottomans ofTurkey in 1517.

Military slavery served the Ottomans well and for a time made possible the continual conquestson which the economy of the state depended. But when the Ottoman expansion ceased, the Sultansfirst allowed the Janissaries to marry and have children and then permitted their sons to enter militaryservice. This made the devshirme unnecessary. It also destroyed the basic purpose of the system, thatof preventing the emergence of a hereditary elite. The institution began to decay, and the slowdisintegration of the Ottoman state proceeded.

The fourth major civilization on the Eurasian continent, that of Europe, developed a complex setof institutions that is more easily understood in comparison with the somewhat simpler cases ofChina, India and the Islamic world. A distinctive feature of European states is that, having escapedfrom tribalism, they then developed an institution contrived by none of the other three civilizations—that of a means for society to control a strong leader.

There emerged in Europe the concept of the rule of law, a consensus among society and the elitethat the ruler was not sovereign, the law was sovereign. Second, Europe and particularly Englanddeveloped ways to hold the king accountable to the law. This structure had the virtue of allowing theruler to be strong but subject to institutional restraint.

The Chinese state, from the days of the Qin, was an efficient, bureaucratized autocracy. Yet to thisday, China has never developed the rule of law. Its emperors, and now the Chinese politburo, makethe law but are not accountable to it and do not have to obey it themselves. China can always force itspeople to build a Great Wall or its equivalent. But its great disadvantage as a strong state is to bedefenseless against a bad emperor, of whom the most recent was Mao Tse-tung.

A central part in the development of European institutions was played by religion. Religion,Fukuyama argues, was critical first in detribalization and second in instituting the rule of law. Theessence of the tribal lineage was the descent of property through the male line. But producing a maleheir under medieval conditions of short life expectancy and high infant mortality was far from a surething. So the tribes had various strategies for keeping wealth within the lineage. These includedcousin marriage, divorce if a woman bore no heir, adoption and the levirate (marrying of widows totheir husband’s brother). In addition, women were not allowed to own property.

The church opposed all these heirship strategies, not because of anything in existing Christiandoctrine but because it had a better idea: that people should leave their property to the church insteadof their heirs. By the end of the 7th century, a third of the productive land in France belonged to thechurch. The tribes of Europe, whether Frankish, Anglo-Saxon, Slavic, Norse or Magyar, found thatconversion to Christianity soon separated them from their property, robbed them of their influenceand paved the way to feudalism.

In the fragmented political conditions of medieval Europe, the church became rich and powerfulbut started to develop tribal or nepotistic problems of its own. Its priests became keenly interested inpassing on their property and offices to their kin. Pope Gregory VII forced priests to become celibateso that their loyalty would be to the church and not to their kin.

Gregory was also at the center of the historic confrontation between the pope and the Holy RomanEmperor over investiture, the question of who had the right to appoint bishops. Gregoryexcommunicated Henry IV, who in turn tried to depose Gregory. But the church prevailed, forcingHenry to come to the pope’s residence at Canossa in 1077 and wait barefoot in the snow for threedays to receive Gregory’s absolution.

The church used its power to back the idea of law, first of the Justinian code, a Byzantinecodification of Roman law that was rediscovered around 1070 AD, and then of canon law, thesynthesis by Gratian of church laws through the centuries. Because law had the church’s authority,sanctioned by a higher power, there emerged in Europe the novel idea that the ruler could not rule indefiance of the law and indeed owed his position to his role in upholding the law.

Feudal Europe was a collection of local barons installed in largely impregnable castles. Kingstended to be the first among equals and had to negotiate with others to exercise power. They wereobliged to take account of the concept that the law and not the king was sovereign. They could not taxor conscript peasants because those rights belonged to the feudal lords. Nor could they seize landbecause of the property rights conferred by the feudal system.

National states emerged in Europe as part of a struggle between the king, the elites and othersources of power. The kings were seldom absolute rulers. The limitation on their powers was takenfurthest in England, where Parliament raised its own armies, executed Charles I and forced James IIto abdicate. The English state thus constructed a system, later followed by other European countries,in which the ruler was subject to the law and in which a representative body held him accountable toit.

“Once this package had been put together the first time,” Fukuyama writes, “it produced a state sopowerful, legitimate, and favorable to economic growth that it became a model to be appliedthroughout the world.” 9

Effects on Social and Individual Behavior

From the broad sweep of Fukuyama’s analysis, a clear pattern emerges. Each of the majorcivilizations of Eurasia developed a characteristic set of institutions in response to its localcircumstances and history. Given that institutions rest on a basis of human social behavior, and thatculture feeds back into the genome, it is plausible to suppose that Chinese, Indians, Ottomans andEuropeans have all adapted over the generations to their particular social conditions. Because of thisevolutionary process, the four civilizations remain distinct today.

The social institutions of the four civilizations had considerable inertia, meaning that theychanged very slowly over time. Institutions that endure for many generations are strong candidates forbeing rooted in a genetically framed social behavior that maintains their stability. East Asiansocieties have a distinctive character, tending to be efficient autocracies. Singapore, for instance,endowed at independence with a cultural heritage of English political institutions, nevertheless hasbecome a looser version of the autocratic Chinese state despite retaining the outward forms of aEuropean one.

A similar continuity in social behavior is evident in Africa, which has consisted largely oftribally organized societies both before and after the episode of colonial rule. European powersprepared their colonies for independence by imposing their own political institutions. But these hadbeen developed over many centuries for the European environment. Considering the long historicalprocess by which Europeans had rid themselves of tribalism, it is hardly surprising that African statesdid not become detribalized overnight. They reverted to the kind of social system to which Africanshad become adapted during the previous centuries.

In tribal systems, people very rationally look to their relatives and tribal groupings for support,not to a central government, whose usual function has been to exact taxes or military service whilegiving back little in return. European or American institutions cannot easily be exported to tribalsocieties like those of Iraq or Afghanistan because they presuppose a large measure of trust towardnon-kin and are designed to operate in the public interest, not to empower the officeholder and histribe.

Variations in human social behavior and in the institutions that embody it have far-reachingconsequences. Developmental economists long ago learned that it is not just lack of capital orresources that keeps countries poor. Billions of dollars’ worth of aid have been poured into Africa inthe past half century with little impact on the standard of living. Countries like Iraq are rich in oil, buttheir citizens are poor. And countries with no resources, like Singapore, are rich.

What makes societies rich or poor is to a great extent their human capital—including the nature ofthe people, their levels of training, the cohesiveness of their societies, and the institutions with whichthey are organized. As Fukuyama notes, “Poor countries are poor not because they lack resources butbecause they lack effective political institutions.” 10

The same conclusion is reached in the recent book Why Nations Fail by the economist DaronAcemog˘lu and the political scientist James Robinson. “Nations fail economically because ofextractive institutions,” they write, meaning institutions that allow a corrupt elite to exclude othersfrom participating in an economy.11 Conversely, they say, “Rich nations are rich largely because theymanaged to develop inclusive institutions at some point during the last 300 years.” 12

Acemog˘lu and Robinson’s theory is discussed further in the next chapter. Of relevance for themoment is that they and Fukuyama have independently concluded that institutions are central to thesuccess and failure of human societies. Less clear is why institutions differ from one society toanother. These differences became most evident during the profound shift in the structure of humansocieties that culminated in the Industrial Revolution.

There have been two major steps in the evolution of human societies, both accompanied bychanges in human social behavior. The first was the transition from the hunter-gatherer existence tothat of settled societies. The settled societies developed agriculture but then stagnated for hundreds ofgenerations in what is known as the Malthusian trap: each increase in productivity was followed by agrowth in population, which ate up the surplus and brought the population back to the edge ofstarvation. The trap could not be escaped until human social nature had undergone a second majortransition. Following is the case for thinking that a deep genetic change in social behavior underlaythe escape from the Malthusian trap and the transition from an agrarian to a modern society.

E

7

THE RECASTING OF HUMANNATURE

We need to confront the most blatant fact that has persisted across centuries of social history—vastdifferences in productivity among peoples and the economic and other consequences of such differences.

—THOMAS SOWELL1

ach of the major civilizations has developed the institutions appropriate for itscircumstances and survival. But these institutions, though heavily imbued with culturaltraditions, rest on a bedrock of genetically shaped human behavior. And when a civilizationproduces a distinctive set of institutions that endures for many generations, that is the sign of

a supporting suite of variations in the genes that influence human social behavior.Historians sometimes speak of national character, but although many might agree that the German

and Japanese characters, say, differ in ways that have deeply affected their respective histories, thereis less agreement on how to define the significant elements of national character. And without someobjective measure, attempts to describe national character easily slip into caricature.

How could any objective measure be found of how human nature changes over time? Surprisinglyenough, such measures exist, even though they are indirect. They come from the work of economichistorians, such as Maristella Botticini and Zvi Eckstein, who have documented the role of educationin Jewish history, and Gregory Clark, who has reconstructed English economic and social behavior inthe 600 years that preceded the Industrial Revolution.

Figure 7.1. Real income per person in England, 1200–2000s

FROM CLARK, FAREWELL TO ALMS

The change brought about by the Industrial Revolution was not a visible alteration of people’slifestyles, such as living in houses instead of the wild, but a quantum leap in society’s productivity.After stagnating for at least the five and a half centuries that can be documented, English wagesstarted to soar in the mid-18th century, reflecting an astonishing increase in the level of productivework.

Productivity increases may seem like something that could excite only an economist, but it madeall the difference to people’s lives. Before the Industrial Revolution, almost everyone but the nobilitylived a notch or two above starvation. This subsistence-level existence was a characteristic ofagrarian economies, probably from the time that agriculture was first invented.

The reason was not lack of inventiveness: England of 1800 possessed sailing ships, firearms,printing presses and whole suites of technologies undreamed of by hunter-gatherers. But thesetechnologies did not translate into better living standards for the average person. The reason was acatch-22 of agrarian economies that dates back probably to the beginning of agriculture.

The catch is called the Malthusian trap because it was described by the Reverend ThomasMalthus in 1798 in his Essay on the Principle of Population. Each time productivity improved andfood became more plentiful, more infants survived to maturity and the extra mouths ate up the surplus.Within a generation, everyone was back to living just above starvation level.

This lack of progress has been documented by the economic historian Gregory Clark of theUniversity of California, Davis. Because of the existence of copious historical information in

England, a country untouched by hostile invasion since 1066 (William of Orange’s invasion in 1688was by invitation), Clark has been able to reconstruct many economic data series such as the real daywages of English farm laborers from 1200 to 1800. Wages were almost exactly the same at the end ofthe period as they had been 600 years earlier. They sufficed to buy a meager diet.

But wages were not constant throughout the period. Between 1350 and 1450 they more thandoubled. The cause was not some miraculous increase in productivity—it was the Black Death,which carried off some 50% of the population of Europe. In a Malthusian-trap world, plagues are ablessing, at least for the survivors. With fewer mouths to feed, everyone ate better, and with a newscarcity of labor, workers could enjoy better wages. This era of plenty lasted a century until risingpopulation numbers closed the jaws of the Malthusian trap once again.

Figure 7.2. English laborers’ real wages, 1200–1800.

FROM CLARK, FAREWELL TO ALMS

In almost all societies since the invention of agriculture most people, aside from the ruling elite,have lived under these harsh conditions. England probably did not differ from other agrarian societiesin Europe and East Asia between 1200 and 1800 except that the economic conditions of itsMalthusian trap are unusually well documented.

Malthus, strangely enough, wrote his essay at the very moment when England, shortly followed byother European countries, was about to escape the Malthusian trap. The escape consisted of such asubstantial increase in production efficiency that extra workers enhanced incomes instead ofconstraining them.

This development, known as the Industrial Revolution, is the salient event in economic history,

yet economic historians say they have reached no agreement on how to account for it. “Much ofmodern social science originated in efforts by late nineteenth and twentieth century Europeans tounderstand what made the economic development path of western Europe unique; yet these effortshave yielded no consensus,” writes the historian Kenneth Pomeranz.2 Some experts argue thatdemography was the real driver: Europeans escaped the Malthusian trap by restraining fertilitythrough methods such as late marriage. Others cite institutional changes, such as the beginnings ofmodern English democracy, secure property rights, the development of competitive markets, orpatents that stimulated invention. Yet others point to the growth of knowledge starting from theEnlightenment of the 17th and 18th centuries or the easy availability of capital.

This plethora of explanations and the fact that none of them is satisfying to all experts pointstrongly to the need for an entirely new category of explanation. Clark has provided one by daring tolook at a plausible yet unexamined possibility—that productivity increased because the nature of thepeople had changed.

Clark’s proposal is a challenge to conventional thinking because economists tend to treat peopleeverywhere as identical. None would suggest that the Stone Age economies in which New Guineansocieties were living when discovered by Europeans had anything to do with the nature of NewGuineans. Provided with the same incentives, resources and knowledge base, New Guineans woulddevelop economies similar to that of Europeans, most economists would say.

A few economists have recognized the implausibility of this position and have begun to ask if thenature of the humble human units that produce and consume all of an economy’s goods and servicesmight possibly have some bearing on its performance. They have discussed human quality, but by thisthey usually mean just education and training. Others have suggested that culture might explain whysome economies perform very differently from others, but without specifying what aspects of culturethey have in mind. None has dared say that culture might include an evolutionary change in behavior,though nor do they explicitly exclude this possibility.

To appreciate the background of Clark’s idea, one has to return to Malthus. Malthus’s essay had aprofound effect on Charles Darwin. It was from Malthus that Darwin derived the principle of naturalselection, the central mechanism in his theory of evolution. If people were struggling on the edge ofstarvation, competing to survive, then the slightest advantage would be decisive, Darwin realized,and the owner would bequeath that advantage to his children. These children and their offspringwould thrive while others perished.

“In October 1838, that is, fifteen months after I had begun my systematic inquiry,” Darwin wrotein his autobiography, “I happened to read for amusement Malthus on Population, and being wellprepared to appreciate the struggle for existence which everywhere goes on from long-continuedobservation of the habits of animals and plants, it at once struck me that under these circumstancesfavorable variations would tend to be preserved, and unfavorable ones to be destroyed. The results ofthis would be the formation of a new species. Here then I had at last got a theory by which to work.”

Given the correctness of Darwin’s theory, there is no reason to doubt that natural selection wasworking on the very English population that provided the evidence for it. The critical issue, then, isthat of just what traits were being selected for.

As it happens, Clark has documented four behaviors that steadily changed in the Englishpopulation between 1200 and 1800, as well as a plausible mechanism of change. The four behaviorsare those of interpersonal violence, literacy, the propensity to save and the propensity to work.

Homicide rates for males, for instance, declined from 0.3 per thousand in 1200 to 0.1 in 1600 andto about a tenth of this in 1800.3 Even from the beginning of this period, the level of personal violencewas well below that of modern hunter-gatherer societies. Rates of 15 murders per 1,000 men havebeen recorded for the Aché people of Paraguay.

Figure 7.3. Homicide rates for males in England, 1190–2000.

FROM CLARK, FAREWELL TO ALMS

Literacy rates can be estimated from the proportion of people who spell out their names ondocuments, such as marriage registers and court documents, instead of signing with an X. The literacyrate among English men climbed steadily from about 30% in 1580 to above 60% by 1800. Literacyamong English women started from a lower base—about 10% in 1650—but had equaled that of menby 1875.4

Figure 7.4. Literary rates among men and women in England, 1580–1920.

FROM CLARK, FAREWELL TO ALMS

Work hours steadily increased throughout the period, and interest rates fell. When inflation andrisk are subtracted, an interest rate reflects the compensation that a person will demand to postponeimmediate gratification by postponing consumption of a good from now until a future date.Economists call this attitude time preference, and psychologists call it delayed gratification. Children,who are generally not so good at delaying gratification, are said to have a high time preference. In hiscelebrated marshmallow test, the psychologist Walter Mischel tested young children as to theirpreference for receiving one marshmallow now or two in fifteen minutes. This simple decision turnedout to have far-reaching consequences: those able to hold out for the larger reward had higher SATscores and social competence in later life. Children have a very high time preference which falls asthey grow older and develop more self-control. American six-year-olds, for instance, have a timepreference of about 3% per day, or 150% per month; this is the extra reward they must be offered todelay instant gratification. Time preferences are also high among hunter-gatherers.

Interest rates, which reflect a society’s time preferences, have been very high—about 10%—fromthe earliest historical times and for all societies before 1400 AD for which there is data. Interest ratesthen entered a period of steady decline, reaching about 3% by 1850. Because inflation and otherpressures on interest rates were largely absent, Clark argues, the falling interest rates indicate thatpeople were becoming less impulsive, more patient and more willing to save.

These behavioral changes in the English population between 1200 and 1800 were of pivotaleconomic importance. They gradually transformed a violent and undisciplined peasant population intoan efficient and productive workforce. Turning up punctually for work every day and enduring eight

hours or more of repetitive labor is far from being a natural human behavior. Hunter-gatherers do notwillingly embrace such occupations, but agrarian societies from their beginning demanded thediscipline to labor in the fields and to plant and harvest at the correct times. Disciplined behaviorswere probably gradually evolving within the agrarian English population for many centuries before1200, the point at which they can be documented.

Growth in productive efficiency makes all the difference to economic output, on which apopulation’s prosperity and survival depend. In 1760, just as the Industrial Revolution was about totake off, 18 hours of labor were required to transform a pound of cotton into cloth. A century later,only 1.5 hours were needed.5

Better technology played a large role in the growth in efficiency. The difference was made not somuch by the major inventions beloved of historians, like Richard Arkwright’s water frame or JamesHargreaves’s spinning jenny, but by a continuous stream of incremental improvements as workersdrew from and improved upon an expanding pool of common technical knowledge.

Clark has uncovered the simple genetic mechanism through which the Malthusian economywrought these changes on the English population: the rich had more surviving children than did thepoor. From a study of wills made between 1585 and 1638, he finds that will makers with £9 or lessto leave their heirs had, on average, just under two children. The number of heirs rose steadily withassets, such that men with more than £1,000 in their gift, who formed the wealthiest asset class, leftjust over four children.

Figure 7.5. Surviving children by assets of the testator.

FROM CLARK, FAREWELL TO ALMS

The English population was fairly stable in size from 1200 to 1760. In this context, the fact thatthe rich were having more children than the poor led to the interesting phenomenon of unremittingsocial descent. Most children of the rich had to sink in the social scale, given that there were toomany of them to remain in the upper class.

Their social descent had the far-reaching genetic consequence that they carried with theminheritance for the same behaviors that had made their parents rich. The values of the upper middleclass—nonviolence, literacy, thrift and patience—were thus infused into lower economic classes andthroughout society. Generation after generation, they gradually became the values of the society as awhole. This explains the steady decrease in violence and increase in literacy that Clark hasdocumented for the English population. Moreover, the behaviors emerged gradually over severalcenturies, a time course more typical of an evolutionary change than a cultural change.

That a profound change in human social behavior should evolve in just a few centuries may seemsurprising, but it is perfectly possible in light of the experiments conducted by Dmitriy Belyaev ondomestication (his experiments on breeding both tamer and fiercer rats were mentioned in chapter 3).Belyaev was a Soviet scientist who believed in evolution despite the anti-genetic views of TrofimLysenko, which were then official doctrine in the Soviet Union. In a remote institute in Novosibirsk,he began to test his theory that ancient farmers had domesticated wild animals by a single criterion,that of tameness. All the many other traits that distinguish domestic animals from their wild forebears—thinner skulls, patches of white hair, floppy ears—had been dragged along in the wake of theselection for tameness, Belyaev supposed.

He began by selecting silver foxes for tameness, taking the remarkable gamble that he would seewithin his lifetime a change that may have taken ancient farmers many hundreds of years toaccomplish. Yet within eight generations, Belyaev had bred silver foxes that would tolerate humanpresence. Just 40 years after the experiment had started and with 30 to 35 generations of breeding, thefoxes were as tame and biddable as a dog. And just as Belyaev had predicted, the tamer foxes hadwhite patches on their coats and droopy ears, even though these traits had not been selected for.6

Belyaev’s work, which did not become known outside the Soviet Union until 1999, demonstratedhow quickly a profound evolutionary change in behavior could occur. Assuming 25 years pergeneration, there would have been 24 human generations between 1200 and 1800, plenty of time for asignificant change in social behavior if the pressure of natural selection were sufficiently intense.

In a broader sense, these changes in behavior were just some of many that occurred as the Englishpopulation adapted to a market economy. Markets required prices and symbols and rewardedliteracy, numeracy and those who could think in symbolic ways. “The characteristics of thepopulation were changing through Darwinian selection,” Clark writes. “England found itself in thevanguard because of its long, peaceful history stretching back to at least 1200 and probably longbefore. Middle-class culture spread throughout the society through biological mechanisms.” 7

Economic historians tend to see the Industrial Revolution as a relatively sudden event and theirtask as being to uncover the historical conditions that precipitated this immense transformation ofeconomic life. But profound events are likely to have profound causes. The Industrial Revolution wascaused not by events of the previous century but by changes in human economic behavior that hadbeen slowly evolving in agrarian societies for the previous 10,000 years.

This, of course, explains why the practices of the Industrial Revolution were adopted so easily byother European countries, the United States and East Asia, all of whose populations had been living

in agrarian economies and evolving for thousands of years under the same harsh constraints of theMalthusian regime. No single resource or institutional change—the usual suspects in most theories ofthe Industrial Revolution—is likely to have become effective in all these countries around 1760, andindeed none did.

That leaves the questions of why the Industrial Revolution was perceived as sudden and why itemerged first in England instead of in any of the many other countries where conditions were ripe.Clark’s answer to both these questions lies in the sudden growth spurt in the English population,which tripled between 1770 and 1860. It was this alarming spurt that led Malthus to write hisforeboding essay on population.

But contrary to Malthus’s gloomy prediction of a population crash induced by vice and famine,which would have been true at any earlier stage of history, incomes on this occasion rose, heraldingthe first escape of an economy from the Malthusian trap. Incomes grew because the productionefficiency of the English economy had been steadily increasing since 1600. It had reached such alevel that, combined with the sudden rise in population, the output of the English economy becamevisibly larger. English workmen contributed to this spurt, Clark drily notes, as much by their labors inthe bedroom as on the factory floor.

The rise in population that made England’s exit from the Malthusian trap so visible was anunrelated event, in Clark’s view. It had no part in causing the escape but merely amplified a processthat was already under way. Clark attributes it to women’s perception that the once substantial risksof death in childbirth had dropped substantially since the 17th century. In 1650 a woman who had theaverage number of children had a 10% chance of dying in childbirth. This formidable risk haddropped to just over 4% by the early 19th century. In 1650, 20% of women never married, and theperceived risk of doing so would have been a rational deterrent. By the early 18th century theproportion of spinsters had fallen to 10%. This and the trend to younger marriages propelled a 40%increase in English fertility between 1650 and 1800.8

Clark’s thesis departs considerably from the mainstream views of economic historians andpolitical economists, most of whom look to institutions to explain major issues such as world povertyand the Industrial Revolution, even though each has a different favorite, whether intellectual propertyrights, the rule of law or parliamentary democracy. Clark dismisses this whole category ofexplanations as insufficient. Many early societies, he says, had all the preconditions for economicgrowth that any World Bank economist could wish for, yet none did so. “Economic historians,” Clarkwrites, “thus inhabit a strange netherworld. Their days are devoted to proving a vision of progressthat all serious empirical studies in the field contradict.” They are thus “trapped in this ever-tightening intellectual death spiral.”

Clark’s book was widely noticed and, unsurprisingly given its heterodoxy, many reviews werecritical. Some reviewers dismissed Clark’s thesis as peremptorily as he had dismissed theirs.Several disagreed with his assertion that England prior to the Industrial Revolution was under a trueMalthusian regime, an issue of contention among economic historians. Others disputed Clark’scalculation about human wealth before agriculture, which has to be inferred from that of living hunter-gatherers. However the strictly economic issues may be resolved, there were relatively few attackson Clark’s proposed mechanism of evolutionary change, the ability of the rich to leave moresurviving children who would spread their genes and behavior through the population as some ofthem descended in social rank.

Clark has since corroborated this mechanism by devising an independent way to check it, basedon the prevalence of surnames. Surnames, being passed from father to son, are effectively propagatedlike the Y chromosome. They track male genes, provided that wives are faithful and no one isadopted, but cases of nonpaternity and adoption were both rare in medieval England. Clark chose twosets of rare surnames, such as Banbricke, Cheveney, Reddyforde, Spatchet and Tokelove, fromEnglish records of 1560–1640. One set belonged to men rich enough to leave a will, the other topeople indicted in Essex courts for burglary, poaching and crimes of violence, and therefore assumedto be among the poorest.

For rare surnames, a large fraction of the holders will typically be related. Clark found that hisrich families survived through the generations much better than the poor ones. By 1851 only 8% of therichest surnames from the 1560–1640 period had disappeared, but 21% of the indicted surnames nolonger existed. The poor have a greater risk of being erased from the gene pool.

But it is not the case, Clark found, that a permanent rich elite survives in perpetuity. Rather, therehas been considerable social mobility in English society. Many of the rare surnames that belonged torich families in 1560–1640 belonged to people in middle- or lower-income occupations, and some ofthe indicted surnames from the earlier period had risen into the gentry by 1851.

“The surname evidence confirms a permanent selection in pre-industrial England for the genes ofthe economically successful, and against the genes of the poor and the criminal,” Clark concludes.“Their extra reproductive success had a permanent impact on the genetic composition of the laterpopulation.” 9

Clark’s data provide substantial evidence that the English population responded genetically to theharsh stresses of a Malthusian regime and that the shifts in its social behavior from 1200 to 1800were shaped by natural selection. The burden of proof is surely shifted to those who might wish toassert that the English population was miraculously exempt from the very forces of natural selectionwhose existence it had suggested to Darwin.

Evolutionary Changes in China

In China, no equivalent data exist to track changes in social behavior through the generations. But thepopulation clearly fell under intense Malthusian pressure as population density increased. Between1350 and 1850, the population expanded from 65 million to 430 million. The only checks on growthwere the Malthusian constraints of high infant mortality and of malnutrition, which lowered fertility.Female infanticide was a principal means of birth control, with the result that many men could neverfind wives.

The harshness of the struggle was made no easier by Chinese inheritance practices, which left anestate to be divided equally between the owner’s sons. A slightly wealthy peasant family might revertto poverty because each son had to start with a much smaller plot of land. “Each generation, a fewwho were lucky or able might rise, but a vast multitude always fell, and those families near thebottom simply disappeared from the world,” writes the essayist Ron Unz.10

A successful family could maintain its economic position over time, Unz writes, “only if in eachgeneration large amounts of additional wealth were extracted from their land and their neighborsthrough high intelligence, sharp business sense, hard work and great diligence.”

Though many poor families perished, there was also movement in the other direction. Within itsauthoritarian structure, Chinese society was reasonably meritocratic. The examinations for themandarinate were in principle open to any adult male. Records available from the Ming (1368–1644)and Qing (1644–1912) dynasties show that more than 30% of those who held the highest mandarinrank came from commoner families.

What effect did these forces have on shaping the genetics and social behavior of the Chinesepopulation? There was evidently high selective pressure for survival skills, given that the poorestindividuals in each generation were eliminated. Those who worked hard, had the right social skillsand made intelligent choices could make their way from the bottom of society to the top in severalgenerations. With a high official’s wealth, they could raise more children, amplifying their successfulgenes before their descendants sank down in status.

Though the Mandarin class might seem at first too small to have exerted any genetic impact on alarge population, the examination system operated over many generations and in a population initiallymuch smaller than that of today. The system, though in rudimentary form, was first instituted by theemperor Wu in 124 BC. Over many generations, it would have disseminated upper-class valuesthroughout society as the more numerous children of the well off descended through the social strata.

The examinees were awarded no marks for originality, however. The exams were based on rotememorization of the Chinese classics and formalized commentaries on the text. “It is obvious thatsuch a system of universal examinations, based on examination questions created by a board of seniorbureaucrats, established an extraordinary uniformity of attitude and opinion,” writes the sociologist ofscience Toby Huff.11 The probable effect of the system was to select for excellent memory, highintelligence and unwavering conformity.

At each cycle, the Chinese population became enriched in survival skills. At the same time,authoritarian regimes ruthlessly repressed dissent, just as they do today. This particular set ofpressures has borne down on the population for 2,000 years, or some 80 generations, with theevolutionary outcome that has made the Chinese a distinctive population. High intelligence may be

one of the behaviors shaped by China’s Malthusian regime—Chinese score above Europeans on IQtests (though so do Koreans and Japanese). Another may be conformity.

The Long Arc of Domestication

The bourgeoisification of the English population between 1200 and 1800 is a minuscule slice, onethat just happens to be documentable, of a long evolutionary process that began in the mists of the lastice age. That process was the civilizing of our remote ancestors, as roving bands of unruly foragerswere transformed into people peaceable enough to settle down together.

The process can be called a domestication because, to judge from the evidence of human fossilremains, it seems to parallel the domestication of animal species by the first farmers. As alreadynoted, human skulls and skeletons from about 40,000 years ago become lighter and less robust, as iftheir owners were no longer fighting one another all the time and could afford more lightly built bonestructures.

This lightening of the bone, a genetically based process, is seen in the fossil remains of specieslike pigs and cattle as they were domesticated from their wild forebears. In people this process,called gracilization, proceeded independently in each of the world’s populations, according to thephysical anthropologist Marta Mirazón Lahr.12 All populations followed this trend save for two at theextremities of the human diaspora, the Fuegians at the tip of South America and the aborigines ofAustralia. Gracilization of the skull is most pronounced in sub-Saharan Africans and East Asians,with Europeans retaining considerable robustness.13

In domestic animals, gracilization is one of the side effects of the taming process. The generalprocess is known as pedomorphic evolution, meaning a trend toward the juvenile form. Thus a dog’sskull and teeth are smaller than those of a wolf, and the shape of the skull resembles that of a juvenilewolf.

The gracilization of human skulls, the primatologist Richard Wrangham has noted, looks just likethe gracilization seen in domestic animals. If this is a side effect of domestication in people too, thenexactly who was doing the taming? The obvious answer, Wrangham suggests, is that people must havebeen taming themselves, by killing or ostracizing individuals who were immoderately violent.Moreover, this ancient process, in his view, is still in motion: “I think that current evidence is thatwe’re in the middle of an evolutionary event in which tooth size is falling, jaw size is falling, and it’squite reasonable to imagine that we’re continuing to tame ourselves,” Wrangham says.14 A likelysignal of the fact that people today are so much tamer than their forebears is that their shrinking jawsdon’t now have room for all the teeth that are programmed into them, so the wisdom teeth must oftenbe removed.

Another insight into the human taming process, from a quite different perspective, has beendeveloped by the sociologist Norbert Elias. Despite working in the shadow of the impending SecondWorld War, Elias was fascinated by the decline of violence in Europe since the Middle Ages. Hewas concerned not with wars between states but with violence in everyday life. He attributed thedecline in personal violence to a long-term psychological change in the population, that of the growthof self-restraint.

A starting point for Elias’s analysis was medieval treatises on polite manners such as the bookOn Civility in Children by the Renaissance scholar Erasmus. In the 16th century, Europeans’everyday social behavior was beyond gross. It was a social world in which books on good etiquettehad to advise people not to blow their noses on the tablecloth nor to snort or smack their lips while

eating. People ate with their hands, the fork being a strange luxury. They blew their noses without theaid of a handkerchief or tissues. They performed many bodily functions in public. Their sensibilitytoward the pain of others was minimal. Public executions were common, often preceded by torture ordismemberment. People behaved with unthinking cruelty toward animals.

A famous midsummer day festivity in 16th century Paris was to burn alive a dozen cats. The kingand queen were usually present, and the king or the dauphin would light a pyre. The cats were thentumbled into the flames from an overhead basket, and the crowd reveled in their cries.

“Certainly this is not really a worse spectacle than the burning of heretics, or the torturings andpublic executions of every kind,” Elias writes. “It only appears worse because the joy in torturingliving creatures shows itself so nakedly and purposelessly, without any excuse before reason. Therevulsion aroused in us by the mere report of the institution, a reaction which must be taken as‘normal’ for the present-day standard of affect control, demonstrates once again the long term changeof personality structure.” 15

Elias argued that between medieval and modern times, a societywide shift has taken place towardgreater sensibility and more delicate manners. Underlying this civilizing process, he believed, was apsychological shift toward greater self-awareness and self-control. He attributed this change inpersonality structure in part to the monopolization of force by the state, meaning that individualsneeded less to resort to violence in self-defense, and in part to the greater interconnectedness of urbansocieties, which required individuals increasingly to attune their conduct to that of others and hence tomoderate their behavior.

Elias was unable to put numbers on his argument, but these are supplied in profusion in avoluminous survey on violence over the ages by the psychologist Steven Pinker. Contrary towidespread belief that the 20th century was more violent than any other, Pinker establishes that bothpersonal violence and deaths in warfare have been in steady decline for as long as records can tell.

In terms of violence between states, the percentage of people who died in warfare is far higher inpre-state societies, to judge by evidence from archaeology and anthropology, than in the states thatsucceeded them. The death rate in pre-state societies averages 15% but had fallen to a mere 3% in thefirst half of the 20th century, a period that includes the two world wars.16

Personal violence too has been in steady decline. Between 1200 and 2000, homicide rates per100,000 people fell from 90 or so to just over one in five European countries.17 Parallel to the fall inviolence is evidence for a general increase in empathy toward the pain of others. People stoppedburning women for suspicion of witchcraft; in England the last witch was burned in 1716. Judicialtorture was gradually abolished in Europe from 1625 onward.18 Finally, empathy compelled theabolition of slavery.

Pinker agrees with Elias that the principal drivers of the civilizing process were the increasingmonopoly of force by the state, which reduced the need for interpersonal violence, and the greaterlevels of interaction with others that were brought about by urbanization and commerce.

The next question of interest is whether the long behavioral shift toward more restrained behaviorhad a genetic basis. The gracilization of human skulls prior to 15,000 years ago almost certainly did,and Clark makes a strong case that the molding of the English population from rough peasants intoindustrious citizenry between 1200 and 1800 AD was a continuation of this evolutionary process. Onthe basis of Pinker’s vast compilation of evidence, natural selection seems to have acted incessantlyto soften the human temperament, from the earliest times until the most recent date for which there is

meaningful data.This is the conclusion that Pinker signals strongly to his readers. He notes that mice can be bred

to be more aggressive in just five generations, evidence that the reverse process could occur just asspeedily. He describes the human genes, such as the violence-promoting MAO-A mutation mentionedin chapter 3, that could easily be modulated so as to reduce aggressiveness. He mentions that violenceis quite heritable, on the evidence from studies of twins, and so must have a genetic basis. He statesthat “nothing rules out the possibility that human populations have undergone some degree ofbiological evolution in recent millennia, or even centuries, long after races, ethnic groups, and nationsdiverged.” 19

But at the last moment, Pinker veers away from the conclusion, which he has so strongly pointedto, that human populations have become less violent in the past few thousand years because of thecontinuation of the long evolutionary trend toward less violence. He mentions that evolutionarypsychologists, of whom he is one, have always held that the human mind is adapted to the conditionsof 10,000 years ago and hasn’t changed since.

But since many other traits have evolved more recently than that, why should human behavior beany exception? Well, says Pinker, it would be terribly inconvenient politically if this were so. “Itcould have the incendiary implication that aboriginal and immigrant populations are less biologicallyadapted to the demands of modern life than populations that have lived in literate state societies formillennia.” 20

Whether or not a thesis might be politically incendiary should have no bearing on the estimate ofits scientific validity. That Pinker would raise this issue in a last minute diversion of a sustainedscientific argument is an explicit acknowledgment to the reader of the political dangers thatresearchers, even ones of his stature and independence, would face in pursuing the truth too far.

Turning on a dime, Pinker then contends that there is no evidence that the decline in violence overthe past 10,000 years is an evolutionary change. To reach this official conclusion, he is obliged tochallenge Clark’s evidence that there was indeed such a change. But he does so with an array ofarguments that seem less than decisive. Clark’s proposed mechanism for the spread of middle-classvalues is based on the fact that the rich, until recently, had more surviving children than did the poor.Pinker objects that this was true of every society, not just the one that later blasted off into theIndustrial Revolution. But this is exactly what Clark’s thesis requires to happen in order for theIndustrial Revolution to spread to other countries. The mechanism was a pre-condition for theIndustrial Revolution wherever it occurred. The specific trigger in England, which explains why itstarted there rather than in any of the other possible birthplaces in Europe and East Asia, was asudden boom in the English population.

Pinker notes that countries without a recent history of selection for middle-class values, likeChina and Japan, can attain spectacular rates of economic growth. But both these countries had longbeen agrarian economies operating, like England, under Malthusian constraints that favored survivalof those who worked hard and saved hard. It was only institutional barriers that delayed thesecountries’ transition to modern economies, and as soon as the barriers were removed, both economiessoared. Last, Pinker cites Clark’s failure to prove that the English are innately less violent than theinhabitants of countries that have not enjoyed an industrial revolution. This seems an unfair criticism,given that the genes underlying violence are for the most part unknown. Nonetheless, the homiciderate in the United States, Europe, China and Japan is less than 2 per 100,000 people, whereas in most

African countries south of the Sahara, it exceeds 10 per 100,000, a difference that does not prove butsurely allows room for a genetic contribution to greater violence in the less developed world.21

The ultimate proof of Clark’s thesis would be discovery of the new alleles that have mediated thesocial behavior required for Europeans and East Asians to make the transition to modern economies.But there are probably many such genes, each with a small and barely detectible effect, so it may takedecades before any come to light.

Meanwhile, his thesis of an evolutionary change provides a powerful explanatory scheme forunderstanding modern societies, especially when combined with the understanding of politicalinstitutions developed by Fukuyama. The countries that have not completed the transition to modernstates retain the default state of human political systems, namely that of tribalism.

Tribal Societies

Africa and much of the Middle East remain largely tribal societies. Tribalism has a bleak reputationbecause tribal organization is incompatible with that of a modern state. That aside, it is an amazinglyingenious way of securing a rough degree of social order without a government, courts, police forceor law books.

In the Arab Middle East, tribalism rests on the idea of group protection. When government doesnot provide the legal system in which a citizen may seek and secure justice, people rely instead ontheir relatives. Someone who is wronged will seek his kin’s backing against the individual whowronged him. The kin group may be just his family, his extended family or his whole tribe, dependingon how far the dispute escalates. A similarly sized group forms around the man he accuses.Hostilities may break out, but the two opposing groups have many inducements to settle, being ofgenerally equal numbers and with each having many members with relatives in the other group. Theindividual’s rights are thus protected, but by the threat of force, not by appeal to law or any formaljudicial process.

What makes the system work is the duty felt by each individual to support his group againstothers, no matter what the personal cost. Failure to support one’s family or tribe in a standoff leads todishonor and means the group’s future support of one’s own cause may be forfeited.

The tribal system is egalitarian, individualistic and secures redress of wrongs with a minimum ofbureaucracy. Despite these outstanding merits, it has grave flaws. It depends on force and grouployalty, not on law. Children are taught from the earliest age that their group is always right and mustbe supported no matter what. Adults follow the ancient rule: support the nearest group of relativesagainst the more distant groups. In terms of national politics, the spirit of tribalism leads to“monopoly of power, ruthless oppression of opponents, and accumulation of benefits,” writes PhilipSalzman, an anthropologist at McGill University who studies nomadic tribes. “In short, it is a recipefor despotism, for tyranny.” 22

The Middle East is, of course, not entirely tribal. It has large urbanized populations. But MiddleEastern governments, in Salzman’s view, follow the traditional Ottoman pattern of being largelypredatory. They extract taxes from their citizens but provide few services except to protect themulcted citizenry from other predators. Many people still rely on the tribal system for justice becausethe government provides none.

The failure to develop modern institutions has led to economic stagnation. There was noeconomic growth in the region in the 25 years after 1980.23 Arab countries may have developed theform of Western institutions, but the practice still escapes them. “All Arab countries need to widenand deepen democratic processes to enable citizens to participate in framing public policy on anequal footing,” write the Arab authors of a United Nations report on Arab development. “A politicalsystem controlled by elites, however decked out with democratic trappings, will not produceoutcomes conducive to human security for all citizens,” they predict.24

The question of why tribalism has persisted in the Middle East but not in Europe has much to dowith the nature of the Byzantine, Arab and Ottoman empires that ruled the region for the past twomillennia. None was overly concerned with the welfare of its citizens. The Byzantine empireextracted heavy taxes and was widely unpopular, one reason for the success of the Arab empire when

the Byzantine empire faltered. The overriding interest of the Umayyad and Abbasid dynasties thatfollowed the Byzantines in ruling the Near East was in steady expansion of Islamic holdings. TheOttoman empire, which eventually displaced the Arabs, was a pure plunder machine. It hadcontinuously to make new conquests and depredations to pay the soldiers on which its imperiumdepended. Under these circumstances, security of persons and property was consistently low formany centuries. There was nothing equivalent to the steady ratchet mechanism that in England enabledthe less violent and more literate to prosper and leave more children like themselves. Because it hasalways been more rational for its inhabitants to trust the tribe more than the state, tribalism in theMiddle East has never disappeared.

In Africa too, tribalism has persisted and interacted poorly with the modern world. Throughoutmuch of Africa, the standard mode of government is kleptocracy; whoever gains power uses it toenrich his family and tribe, which is the way that power has always been used in tribal systems.Extractive institutions, as defined by Acemog˘lu and Robinson, are prevalent in Africa, particularlyin countries rich in natural resources.

Despite substantial amounts of Western aid, many African countries are little better off than theywere under colonial rule. Corruption is rampant. Many services for the poor are siphoned off byelites who leave only a trickle for the intended recipients. Some African countries have lower percapita incomes now than they had in 1980 or, in some cases, in 1960. “Half of Africa’s 800 millionpeople live on less than $1 a day,” writes the journalist and historian Martin Meredith. “It is the onlyregion where school enrolment is falling and where illiteracy is still commonplace. . . . It is also theonly region where life expectancy is falling.”

The root of the problem, Meredith believes, is that African leaders have failed to provideeffective government. “Africa has suffered grievously at the hands of its Big Men and its rulingelites,” he writes. “Their preoccupation, above all, has been to hold power for the purpose of self-enrichment. . . . Much of the wealth they have acquired has been squandered on luxury living orstashed away in foreign bank accounts or foreign investments. The World Bank has estimated that40% of Africa’s private wealth is held offshore. Their scramble for wealth has spawned a culture ofcorruption permeating every level of society.” 25

As serious as the flight of capital is the flight of able and educated people. “The most commonrequest to a white visitor to Africa these days, particularly from young people, is for help with a visato Europe or America. Some 70,000 skilled people are reported to be fleeing the continent eachyear,” writes journalist Patrick Dowden.26

Africa south of the Sahara is wracked by frequent violence, with about a third of its countriesbeing at present involved in conflicts. Sudan, since its independence in 1956, has been locked in aseries of civil wars. The Congo is a region of unending misery. Nigeria, cursed with oil, is a sea ofcorruption riven by religious and regional disputes.

Despite all these serious problems, the GNP of the region has recently started to grow, expandingat an average rate of 4.7% a year between 2000 and 2011. Though the increase in GNP masks theextreme inequality that still persists, there are several long-term trends that point to sustainablegrowth. Overpopulation is not usually regarded as a blessing, yet demographic pressure has played aprime role in the urbanization of Europe and East Asia, though so far not Africa. This, however, maybe about to change. “No country or region,” say two World Bank economists, Shantayanan Devarajanand Wolfgang Fengler, “has ever reached what the World Bank regards as high-income status with

low levels of urbanization. African populations have traditionally been mostly rural, but the cities ofsub-Saharan Africa are growing at astonishing rates.” Their projection is that in another 20 years,most of the region’s population will be urban, as is the case in the rest of the world.27

Urbanization and empire building generated the first civilizations in Egypt, Mesopotamia, Chinaand the Americas. Whether it is necessary for Africa to take the same path to create modern states isfar from clear. But fierce pressures are clearly at work in the continent, and people will adapt tothem. These adaptations may include a reduction of tribalism.

If running a productive, Western-style economy were simply a matter of culture, it should bepossible for African and Middle Eastern countries to import Western institutions and businessmethods, just as East Asian countries have done. But this is evidently not a straightforward task.Though it was justifiable at first to blame the evils of colonialism, two generations or more have nowpassed since most foreign powers withdrew from Africa and the Middle East, and the strength of thisexplanation has to some extent faded.

Tribal behavior is more deeply ingrained than are mere cultural prescriptions. Its longevity andstability point strongly to a genetic basis. This is hardly surprising, given that tribes are the defaulthuman social institution. The inbuilt nature of tribalism explains why it took so many thousands ofyears for East Asians and later Europeans to break free of its deadening embrace. It’s this escape thatis so unexpected, not that the populations of Africa and the Middle East have so far lacked theopportunity to lose the ancient heritage of tribal political behavior.

The Escape from Tribalism and Poverty

The entry to the modern industrial world has two principal requirements. The first is to developinstitutions that enable a society to break away, at least to some substantial extent, from the defaulthuman institution of tribalism. Tribalism, being built around kinship ties, is incompatible with theinstitutions of a modern state. The break from tribalism probably requires a population to evolve suchbehaviors as higher levels of trust toward those outside the family or tribe. A second requiredevolutionary change is the transformation of a population’s social traits from the violent, short-term,impulsive behavior typical of many hunter-gatherer and tribal societies into the more disciplined,future-oriented behavior seen in East Asian societies and documented by Clark for English workers atthe dawn of the Industrial Revolution.

Looking at the three principal races, one can see that each has followed a different evolutionarypath as it adapted to its local circumstances. From an evolutionary perspective, no path is better thanany other—nature’s only criterion for success is how well each is adapted to its local environment.

Consider first Caucasians, the grouping of populations that includes Europeans, MiddleEasterners and people of the Indian subcontinent (Indians and Pakistanis). Most European countriesfollowed England almost immediately in transitioning to modern economies. Their populations, likethat of England, had abandoned tribalism in the early Middle Ages. Europeans had long lived in thesame Malthusian economies that Clark has documented for England. Within a few decades, all hadbeen able to import English production methods and develop modern economies. Thus the IndustrialRevolution was not particularly English, given that the evolutionary change that preceded it hadoccurred throughout Europe and East Asia. For an unrelated reason—the population spurt describedabove—the Industrial Revolution just happened to manifest itself first in the English economy.

Why did the Industrial Revolution not spread so fast to China or Japan, which differed little fromEngland in the state of their labor, land and capital markets? Clark argues that their upper classeswere less fertile than their English counterparts, so that the engine that drove the spread of bourgeoisvalues through the population operated somewhat more slowly in East Asia.28 The economic historianKenneth Pomeranz, on the other hand, argues that there were few significant differences betweenEurope and China until England, with access to the extensive resources in its Caribbean andAmerican colonies, was able to escape the constraints that held China back. He concludes that“forces outside the market and conjunctures beyond Europe deserve a central place in explaining whywestern Europe’s largely unexceptional core achieved unique breakthroughs and wound up as theprivileged center of the nineteenth century’s new world economy, able to provide a soaringpopulation with an unprecedented standard of living.” 29

From an evolutionary standpoint, the populations of both Europe and East Asia had been primedby the selective pressures of their agrarian economies to escape the Malthusian trap, and it makeslittle difference which particular factor or event was the trigger for the transition to begin. It seemsmore likely that institutions, rather than human nature, were the impediment to East Asian progress.The peoples of China, Japan and Korea were fully ready to embrace the Industrial Revolution andmarket economies once the necessary institutions were in place. For Japan, that was after the MeijiRestoration of 1868; for China, after the reforms initiated by Deng Xiaoping after 1979.

In East Asian populations, history has performed an instructive control experiment with the case

of Korea. North and South Koreans are probably very similar to one another genetically, yet NorthKoreans are poor while South Korea has developed a tiger economy that is post-Malthusian, modernand prosperous. The difference, evidently, lies not in the two countries’ genes or geography but in thefact that the same set of social behaviors can support either good or bad institutions. Before 1945,Korea was a single country. After partition, North Korea instituted a collectivist system and acommand economy run by a hereditary elite. North Korea lacks property rights or a reliable courtsystem, giving people little incentive to invest for the future, since the state can confiscate property atwill. Its population is denied education except for state propaganda. South Korea, by contrast, wasdirected toward a market economy by its first two authoritarian leaders.

By 2011, South Koreans had become almost 18 times richer than their former compatriots inNorth Korea, with an estimated GDP per capita of $32,100 compared with $1,800. “Neither culturenor geography nor ignorance can explain the divergent paths of North and South Korea. We have tolook at institutions for an answer,” say Acemog˘lu and Robinson in Why Nations Fail.30

The fact that China, Japan and South Korea developed modern economies so easily, once theappropriate institutions were in place, is evidence that their populations, like those of Europe, hadundergone equivalent behavioral changes to those documented in England.

Another major impact on the Chinese population would have been urbanization. Cities are anenvironment that rewards literacy, the manipulation of symbols, and high-trust trade networks. Withprolonged urbanization, those who mastered the skills of urban living would have had more children,and the population would have undergone the genetic changes that accomplish the adaptation to urbanlife. In Western countries, the affluent now tend to have fewer children, and China has had its onechild policy, both of which set up different evolutionary forces. But until modern times, populationsin both Europe and East Asia have partially been shaped by the ability of the rich to raise moresurviving children, another instance of the ratchet of wealth.

Turning to the third of the major races, the population of Africa south of the Sahara, the transitionof these countries to modern economies has proved considerably slower. Africa is heavily beset withpoverty, disease, war and corruption. Despite copious amounts of foreign aid, its living standardshave failed to show substantial improvement over those attained under colonial rule. A recent spurt ineconomic activity in several countries has still not closed the widening gap with East Asia andEurope.

Yet 50 years ago, Africans were as poor as many East Asians. Why has it been easy enough forEast Asians to make the transition to modern economies but so hard for Africans?

As discussed, one reason is tribalism. African countries have not developed the institutions toreplace tribalism, an essential development for a modern state. African populations have not gonethrough the same Malthusian wringer that shaped the behavior of the European and East Asianpopulations. In Africa, population pressure has long been much lower than in Europe and Asia,probably because of poor soils and adverse climates that have restrained food production. Stateformation, as mentioned, depends on warfare between sizable polities that are forced to competebecause of geographical constraints, such as living along a fertile river valley. But intense, large-scale warfare is unlikely to occur until population densities have become so high that people havefew other choices.

Until modern times, populations in Africa remained very low, constricted by disease and thegrudging fertility of the soil in many tropical regions. For lack of demographic pressure, they thus

escaped the urbanization and regimentation to which the populations of Europe and East Asia weresubjected for many generations.

From an evolutionary perspective, African populations were just as well adapted to theirenvironment as were those of Europe and Asia to theirs. Small, loosely organized populations werethe appropriate response to the difficult conditions of the African continent. But they were notnecessarily well suited to the high efficiency economies to which European and East Asianpopulations had become adapted. From this perspective, it is understandable that African countriesshould take longer to make the transition to modern economies.

Turning to the Near East, these populations belong, along with Europeans, to the Caucasiangrouping. But unlike Europeans and East Asians, they have lacked the shaping experience of livingunder relatively stable agrarian economies. The Byzantine, Arab and Ottoman empires that held swayin the region for the past 1,500 years were predatory regimes whose purpose was not to serve theirpopulations but to extract wealth from them for the support of the ruling elite. Generations of such rulehabituate people, quite rationally, to look to their family and tribe for help, not the government. Andunder these conditions, it is hard for tribal behaviors to give way to the more trusting behaviors foundin modern economies. Countries of the Near East, particularly Arab states, have not yet developedinstitutions to transcend tribalism and hence face serious obstacles in achieving the transition tomodern economies.

These obstacles presumably reside at the level of societies and less with the abilities of theirindividual members. A worldwide diaspora of accomplished and wealthy Lebanese, for instance, isproof of how successful Lebanese can be outside of Lebanon, a situation similar to that of theoverseas Chinese communities during the past two centuries. But China has since been able toimprove its institutions more easily than has Lebanon.

The Problem of Economic Development

The view of economic development generally taken by economists is that people have little or nothingto do with it. Since all humans are identical units that respond the same way to incentives, at least ineconomic theory, then if one country is poor and another rich, the difference cannot have anything todo with the people but must lie in institutions or access to resources. Just supply enough capital andimpose business-friendly institutions, and robust economic growth will surely follow. Strongevidence to this effect seemed to be furnished by the Marshall Plan, which helped revive Europeaneconomies after the Second World War.

On the basis of this theory, the West has spent some $2.3 trillion in aid over the past 50 yearswithout managing to improve African living standards. Could something be not quite right with thetheory? Might the human units of the world’s economies be less completely fungible than economictheory assumes, with the consequence that variations in their nature, such as their time preference,work ethic and propensity to violence, have some bearing on the economic decisions they make?

To account for the discrepancy between theory and practice, a few scholars interested indevelopment have begun to suggest that maybe people do matter after all. Their suggestion is thatculture plays an important role in people’s economic behavior.

In the early 1960s Ghana and South Korea had similar economies and levels of gross nationalproduct per capita. Some thirty years later, South Korea had become the 14th largest economy in theworld, exporting sophisticated manufactures. Ghana had stagnated, and GNP per capita had fallen toone fifteenth that of South Korea. “It seemed to me that culture had to be a large part of theexplanation,” the political scientist Samuel Huntington remarked in pondering this divergence ofeconomic fates. “South Koreans valued thrift, investment, hard work, education, organization, anddiscipline. Ghanaians had different values.” 31

Even the economist Jeffrey Sachs, a tireless advocate of increased aid, has conceded thepossibility that culture might play some minor role in differences in economic development. Although“the great divisions between rich and poor countries involve geography and politics,” he writes,“nonetheless, there are indeed some hints of culturally mediated phenomena. Two are most apparent:the underperformance of Islamic countries in North Africa and the Middle East and the strongperformance of tropical countries in East Asia that have an important overseas Chinese community.”32

But if culture explains economic performance in even a few groups, it could play a significantrole in all economies. Scholars fear pursuing the issue further because they are not really usingculture in just its accepted meaning of learned behavior. Rather, it is a catchall word that includespossible reference to a concept they dare not discuss, the possibility that human behavior has agenetic basis that varies from one race to another.

The sociologist Nathan Glazer, for instance, all but admits that culture and race are validexplanatory variables, yet ones that cannot be used: “Culture is one of the less-favored explanatorycategories in current thinking. The least favored, of course, is race. . . . We prefer not to refer to ormake use of it today, yet there does seem to be a link between race and culture, perhaps onlyaccidental. The great races on the whole are marked by different cultures, and this connectionbetween culture and race is one reason for our discomfort with cultural explanations,” he writes.33

Several social behaviors that economists have identified as obstacles to progress are ones thatcould well have a genetic basis. One is the radius of trust, which can extend to strangers in moderneconomies but is confined to family or tribe in premodern ones. “Seen from the inside, Africansocieties are like a football team in which, as a result of personal rivalries and a lack of team spirit,one player will not pass the ball to another out of fear that the latter might score a goal. How can wehope for victory? In our republics, people outside of the ethnic ‘cement’ . . . have so littleidentification with one another that the mere existence of the state is a miracle,” writes DanielEtounga-Manguelle, a Cameroonian economist.34

The willingness to save and delay gratification is a social behavior that Clark finds graduallyincreased in the English population in the 600 years before the Industrial Revolution. Conversely, thepropensity to save seems considerably weaker in tribal societies. This could be in large measurebecause such societies are poorer; everyone saves more as they get richer. But the disinclination tosave in tribal societies is linked to a strong propensity for immediate consumption. To quote Etounga-Manguelle again, “Because of the rapport that the African maintains with time, saving for the futurehas a lower priority than immediate consumption. Lest there be any temptation to accumulate wealth,those who receive a regular salary have to finance the education of brothers, cousins, nephews, andnieces, lodge newcomers, and finance the multitude of ceremonies that fill social life.”

There is reasonable evidence that trust has a genetic basis, though whether it varies significantlyamong ethnic groups and races has yet to be proved. The aspects of culture that some economists havebegun to see as relevant to economic performance could well have a genetic basis, even though thishas yet to be proved or even seriously investigated. Social behavior, whatever its degree of culturalor genetic foundation, can be modulated by education and incentives, so a better understanding of itsrole in economic performance might have practical consequences. Those who ignore culture alsoignore “an important part of the explanation of why some societies or ethno-religious groups do betterthan others with respect to democratic governance, social justice, and prosperity,” writes thedevelopment expert Lawrence Harrison.35

The link between race and culture is evident in the well-known natural experiment put in motionby human migrations. Members of various races have migrated to a range of different environmentsbut maintained their distinctive behaviors in many countries over many generations. The economistThomas Sowell has documented many of these episodes in his trilogy about race and culture.

Consider the case of Japanese immigrants to the United States. They arrived as agriculturallaborers in Hawaii in the late 19th century to work on the sugar crop and later moved to the mainland.The first generation were farmworkers and domestic servants and gained a reputation for hard work.The second generation, with the advantage of American college educations, sought to learnprofessions. By 1959 Japanese Americans were earning the same family income as EuropeanAmericans, and by 1990 their income was 45% higher.36

In Peru, Japanese workers achieved a reputation for hard work, reliability and honesty andbecame successful in both farming and manufacturing. In Brazil, Japanese settlers were found to beefficient, industrious and law-abiding. As they prospered, they entered banking and manufacturing andcame to own almost 75% as much land in Brazil as there is in Japan. In these three different cultures,the Japanese were successful because of diligent work habits, with the first generation beingprodigious farmers and the second generation moving into the professional world.

The overseas Chinese were equally productive immigrants, especially in Southeast Asia, where

they worked indefatigably and built up businesses. Most Chinese immigrants began as farm laborerswith a prodigious capacity for hard work. In Malaysia, Chinese doing unskilled labor alongsideMalays on the rubber plantations would produce twice the output. As early as 1794, a British reporton the Malaysian settlement of Penang labeled the Chinese as “the most valuable part of ourinhabitants.” 37

Chinese enterprises were typically family owned and family run, even when they grew intosizable corporations. They clung to their own values and work ethic among populations who oftentook a more relaxed view of how time should be spent. In the Caribbean, Sowell writes, the Chinese“remained outside the value system of West Indian society—unaffected by its Creole patterns ofconspicuous consumption, distribution of largesse, forgiveness of debts, and other traits that operateagainst business success.” 38

Small Chinese populations in Thailand, Vietnam, Laos and Cambodia grew to playdisproportionate roles in these countries’ economies. They dominated the thriving economy ofSingapore and were so productive in Indonesia that their success provoked envy and repeatedmassacres. By 1994 the 36 million Chinese working overseas produced as much wealth as the 1billion people in China.39

Significant Chinese immigration into the United States began in 1850 with the California goldrush. Often allowed to mine only those areas that others deemed unprofitable, the Chinese persistedand flourished where others couldn’t. Chinese workers built much of the Central Pacific Railroad andat one time supplied 80% of all agricultural workers in California.

Their success provoked a series of discriminatory laws advocated by those who could notcompete against them. Excluded from one industry after another, by 1920 more than half of allChinese in the United States worked in laundries and restaurants. As soon as adverse laws wererepealed, a younger generation of Chinese Americans started to go to college and enter professionaljobs. By 1959, Chinese family income had drawn level with the U.S. average, and by 1990 themedian family income was 60% higher than that of non-Asian Americans.40

Among non-Asian immigrants, Jews, a special case, are discussed in the next chapter. Germansimmigrated to Russia, the United States and Australia, earning a reputation in all three countries fortheir orderliness and discipline. In Russia they filled many important professions to such a degree thatby the 1880s Germans occupied 40% of the Russian army’s high command and 57% of the foreignministry staff. At one time almost the entire membership of the St. Petersburg Academy of Scienceswas German.41

In the United States, many German immigrants took to farming and were more productive thanmany other groups. “They were widely known for their industriousness, thrift, neatness, punctuality,and reliability in meeting their financial obligations,” Sowell reports. In Australia they becamesuccessful farmers, recognized for their hard work, thoroughness and respect for the laws.

The grand theme of Sowell’s trilogy is that races have their own strong cultures that shape theirbehavior, in contrast to the common view that society determines the fates of its minority groups. Hispurpose is to demonstrate the persistence of racial, ethnic and national cultures but without exploringwhy such cultural traits endure. He has nothing to say about genetics. But traits that endure, as he hasshown, in a range of different environments and from one generation to another are of course quitelikely to be anchored by a genetic adaptation; otherwise they would quickly disappear as immigrantgroups adapted to their hosts’ dominant culture.

Behaviorial traits like industriousness are particularly likely to be retained, but the universalinstinct to conform to social rules seems to ensure that the political behaviors of the host countrysupplant those of the immigrants. Chinese Americans do not organize themselves into authoritarianstructures, nor Arab and African Americans into tribal ones.

There is in fact a straightforward explanation for the behaviors of all the migrant groupsdescribed by Sowell, in terms of the ratchet of wealth explanation given above for the IndustrialRevolution. Populations like Europeans and East Asians, who have adapted, during centuries ofliving in agrarian systems, to the exigencies of running efficient economies, are at considerableadvantage when migrating to other countries. Hard work, efficiency and group cohesion characterizethe behavior of East Asian and European migrant groups. It is particularly notable that the Japaneseand Chinese should attain higher than average standards of living in the United States, competingagainst a predominantly European population. The longer history of urbanization in East Asia mayunderlie part of this competitive advantage.

Populations that have adapted historically to market economies can still fall short of successduring periods when they adopt inefficient institutions, such as China under Mao or North Koreaunder the Kim family dictatorship. When North Korea adopts market-friendly institutions, a safeprediction is that it would in time become as prosperous as South Korea. It would be far less safe topredict that Equatorial Guinea or Haiti needs only better institutions to attain a modern economy; theirpeoples may not have yet had the opportunity to develop the ingrained behaviors of trust, nonviolenceand thrift that a productive economy requires.

The IQ and Wealth Hypothesis

Standing in sharp contrast to the economists’ working assumption that people the world over areinterchangeable units is the idea that national disparities in wealth arise from differences inintelligence. The possibility should not be dismissed out of hand: where individuals are concerned,IQ scores do correlate, on average, with economic success, so it is not unreasonable to inquire if thesame might be true of countries.

The global IQ/wealth thesis is connected with the interminable debate about black and white IQdifferences in the United States, but it involves somewhat different issues and builds more on that partof the evidence about which both sides agree.

The two camps in the IQ debate are known as hereditarians and environmentalists. Both sidesgenerally agree that when IQ tests are administered in the United States, European Americans score100 (by definition—their scores are normalized to 100), Asian Americans score 105 and AfricanAmericans score 85 to 90. The African American score is noticeably lower than the European score(15 points, or one standard deviation, say the hereditarians; 10 points, say the environmentalists). Somuch is agreed. The controversy arises in interpreting the gap between the European and AfricanAmerican scores. The hereditarians say the difference in scores is due 50% to environmental reasonsand 50% to genetics, although they sometimes change the mix to 20% environment and 80% heredity.The environmentalists assert that the entire gap is due to environmental impediments and that if thesewere removed, the gap would ultimately disappear altogether.

The heritability of intelligence, the measure which the two sides interpret so differently, does notrefer, as easily might be supposed, to the extent to which intelligence is governed by the genes. Itrefers to the variation in intelligence within a population, and specifically to the extent to which thisvariation is genetic. A trait could be under complete genetic control, but if there were no variation inthe population, its heritability would be zero. Intelligence is almost certainly under genetic influencebut none of the responsible alleles has yet been identified with any certainty, probably because eachmakes too minute a contribution to show up with present methods.42

The two sides in the IQ debate are not so terribly far apart on the facts, given that both sides agreethat environmental factors are involved. The hereditarians concede that if an adjustment is made forsocioeconomic status, with which IQ score is correlated, then African American scores would rise 5points, to 90. That is not so much greater than the gap that separates Asian Americans from EuropeanAmericans, about which no one seems to be bothered.

Why, then, is the debate so heated? The acrimony arises because the two positions lead todifferent policy choices. The hereditarians say that since the IQ gap is substantially innate, the HeadStart early education program has failed, as was predicted by Arthur Jensen in 1969, and so willsimilar interventions. The environmentalists deny this, saying the gap in educational attainment isclosing, and that it is the racist nature of society that impedes African American advancement.

That issue needn’t be resolved here. The question of global IQ is a somewhat less fraught issueand is of considerable evolutionary interest because intelligence reflects evolutionary changes in thebrain and behavior.

The principal proponents of the global IQ/wealth thesis are Richard Lynn, a psychologist at theUniversity of Ulster, and Tatu Vanhanen, a political scientist at the University of Tampere in Finland.

They have gathered data from around the world and worked out the correlation between intelligence,as measured by IQ tests, and various criteria of economic success, such as gross national product percapita. Their findings are published in two books, IQ and the Wealth of Nations (2002) and IQ andGlobal Inequality (2006).

The world’s average IQ, they report, is 90. Broken down by race, the IQ of East Asian nations is105, the European score is 99, and sub-Saharan Africa’s is 67.43 The authors note that the sub-Saharan African score would be considerably higher but for malnutrition and ill health.

Lynn and Vanhanen argue that IQ scores must be measuring something significant because IQcorrelates well with measures of educational attainment. The scores are indeed strongly associated,they say, with what economists call human capital, which includes training and education.

Turning to economic indicators, they find that national IQ scores have an extremely highcorrelation (83%) with economic growth per capita and also associate strongly with the rate ofeconomic growth between 1950 and 1990 (64% correlation).44

“Our argument is that differences in the average mental abilities of populations measured bynational IQ provides the most powerful, although not complete, theoretical and empirical explanationfor many types of inequalities in human conditions,” Lynn and Vanhanen conclude.45 It follows fromthis conclusion that not much can be done to reduce inequities in national wealth. “The gap betweenrich and poor countries can be expected to persist as far as it corresponds to differences in nationalIQs,” they say.46

It may seem intuitively plausible that a more intelligent population might garner more wealth thana less intelligent one. But intelligence is a quality of individuals, not of societies. A society of strongmen might easily be defeated by weaker men if the weaklings are more cohesive and fight harder.Like strength, the property of individual intelligence does not necessarily transfer from individuals tothe society of which they are part.

And indeed with Lynn and Vanhanen’s correlations, it is hard to know which way the arrow ofcausality may be pointing, whether higher IQ makes a nation wealthier or whether a wealthier nationenables its citizens to do better on IQ tests. The writer Roy Unz has pointed out from Lynn andVanhanen’s own data examples in which IQ scores increase 10 or more points in a generation when apopulation becomes richer, showing clearly that wealth can raise IQ scores significantly. EastGerman children averaged 90 in 1967 but 99 in 1984. In West Germany, which has essentially thesame population, averages range from 99 to 107. This 17 point range in the German population, from90 to 107, was evidently caused by the alleviation of poverty, not genetics.

There is a 10 to 15 point difference in IQ scores between the richer and poorer countries ofEurope, yet these differences disappear when the inhabitants migrate to the United States, so thedifferences are evidently an environmental effect, not a genetic one. If European IQ scores can varyso widely across different decades and locations, it is hard to be sure that any other ethnic differencesare innate rather than environmental. Lynn and Vanhanen’s book “constituted a game-ending own-goalagainst their IQ-determinist side,” Unz concluded, but “neither of the competing ideological teamsever noticed.”

Lynn and Vanhanen do in fact acknowledge the role of wealth in enhancing IQ scores. But thedifficulty of quantifying the IQ-enhancing effect of wealth seriously weakens the ability of IQ scoresto explain wealth. More generally, it may be hazardous to compare the IQ scores of different races ifallowance is not made for differences in wealth, nutrition and other factors that influence IQ.

East Asia is a vast counterexample to the Lynn/Vanhanen thesis. The populations of China, Japanand Korea have consistently higher IQs than those of Europe and the United States, but their societies,despite their many virtues, are not obviously more successful than those of Europe and its outposts.Intelligence can’t hurt, but it doesn’t seem a clear arbiter of a population’s economic success. What isit then that determines the wealth or poverty of nations?

Institutions and National Failure

A much praised inquiry into the nature of national poverty is the recent book Why Nations Fail, byDaron Acemog˘lu, an economist, and James Robinson, a political scientist. As noted earlier in thischapter, they agree with Fukuyama in regarding institutions as critical to understanding how humansocieties work. And they arrive at this conclusion by an independent route. Fukuyama identifies therole of institutions largely through historical patterns; Acemog˘lu and Robinson emphasize politicaland economic analysis.

Most of the inequality between the countries of the world has emerged since the IndustrialRevolution, Acemog˘lu and Robinson note, before which time standards of living were almostuniformly low for almost everyone except for the handful of people in each nation’s ruling class. Alist of the 30 richest countries today would include Britain and the countries to which the IndustrialRevolution quickly spread—Western Europe and the initially British settlements of the United States,Canada and Australia—and Japan, Singapore and South Korea. The 30 poorest countries would bemostly in sub-Saharan Africa, joined by Afghanistan, Haiti and Nepal. Going back a century, the listof countries in the top and bottom 30 would be much the same, save that Singapore and South Koreahadn’t joined the ranks of the richest.

Surely economists, historians or other social scientists must have devised some convincingexplanation for this substantial and enduring inequality? “Not so,” say Acemog˘lu and Robinson:“Most hypotheses that social scientists have proposed for the origins of poverty and prosperity justdon’t work and fail to convincingly explain the lay of the land.” 47

Their thesis is that there are bad and good institutions or, as they term them, extractive andinclusive institutions. The bad, extractive institutions are those in which a small elite extorts the mostit can from a society’s productive resources and keeps almost everything for itself. The elite opposestechnological change because it is disruptive of the political and economic order required to maintaintheir position. Through its own greed, the elite impoverishes everyone else and prevents progress. Apermanent vicious circle between the society’s extractive political and economic institutionsmaintains continual stagnation.

Good, inclusive institutions, by contrast, are those in which political and economic power iswidely shared. The rule of law and property rights reward endeavor. No sector of society is powerfulenough to block economic change. A virtuous circle between politics and economics maintainsincreasing prosperity.

The archetype of inclusive institutions, in Acemog˘lu and Robinson’s view, was the GloriousRevolution of 1688, in which England replaced its French-leaning king, James II, with his son-in-lawWilliam of Orange, a switch that consolidated Parliament’s control over the king. Both political andeconomic institutions became more inclusive, creating incentives for entrepreneurs and laying thebasis for the Industrial Revolution.

This shift to inclusive institutions was so decisive, in Acemog˘lu and Robinson’s view, that it isin fact the only condition that distinguishes rich countries from poor ones. Comparing England andEthiopia, one of the world’s richest countries and one of the poorest, they assert that “the reasonEthiopia is where it is today is that, unlike in England, in Ethiopia absolutism persisted until therecent past.” 48

They concede that absolutist regimes can generate prosperity for a while, for instance byswitching manpower from agriculture to industry. But these one-off expedients were temporary in thecase of the Soviet Union; and in China too, political repression will also, they predict, cause theChinese economy to falter unless it makes its political institutions more inclusive.

If inclusive institutions are the only thing that matters in achieving prosperity, it follows thatforeign aid is useless unless it begins with institutional reform. But this is almost never the case,because such conditions are resisted by the ruling elites whose interests would be imperiled by thereforms. As Acemog˘lu and Robinson explain, “Countries need inclusive economic and politicalinstitutions to break out of the cycle of poverty. Foreign aid can typically do little in this respect, andcertainly not with the way that it is currently organized.” 49

As a description of the current state of affairs, Acemog˘lu and Robinson’s thesis seemsreasonably satisfying. But the authors have great difficulty explaining how good institutions arise orhow they can be established in a country that doesn’t have them. “The honest answer of course is thatthere is no recipe for building such institutions,” they admit.

They have no recipe to offer because they believe that good institutions have emerged as a matterof chance, as random ripples on the inexplicable tides of history. They argue that institutions changebecause of “institutional drift,” a phenomenon they explicitly compare to the random process ofgenetic drift. They think that institutions are shaped by history but that history moves in a “contingentpath,” meaning that it is a succession of accidents. Even the Glorious Revolution was not inevitable,since its emergence “was in part a consequence of the contingent path of history.” 50

Acemog˘lu and Robinson argue that bad institutions get replaced with good ones, as in England’sGlorious Revolution or Japan’s Meiji Restoration, because of “critical junctures” in historycombined with “propitious existing institutions.” They assert, “In addition some luck is key, becausehistory always unfolds in a contingent way.” 51

Luck is an explanation? Not divine providence, or some sign of the zodiac? The authors aredriven to reach for such unsatisfying explanations because they have ruled out the obvious possibilitythat variations in human behavior are the cause of good or bad institutions. They are thus forced backon nonexplanations like luck and the contingent path of history.

The wealth of human societies has not followed some random path over the past millennium, butrather, as Acemog˘lu and Robinson observe, a part of the world has grown steadily and vastly richerover the past 300 years. This is not an accident or luck, and a reasonable explanation is available interms of human evolution.

The Meso-Industrial Age

The explanation is that there has been an evolutionary change in human social behavior that hasfacilitated the new, post-tribal social structure on which modern societies are based. Rich countrieshave non-tribal, trust-based economies and favorable institutions. Poor countries are those that havenot fully escaped from tribalism and labor under extractive institutions that reflect their limited radiusof trust.

The present world situation is analogous to the mixed social structures that prevailed during theMesolithic Age, which lasted from about 10,000 to 5,000 years ago in Europe. People using the newfarming technologies had begun to invade Europe from the Near East. The hunter-gatherer people whothen occupied Europe were either killed or adopted into the new farming communities. The hunter-gatherers used an old kit of stone tools, which archaeologists refer to as Paleolithic, in contrast to thenew kit used by the farmers, known as Neolithic. The transition period from the Paleolithic to theNeolithic, during which the settled behavior became increasingly dominant in Europe, is thereforeknown as the in-between or Mesolithic Age.

The world is at present in a similar transition period, in which some populations have emergedfrom the shaping forces of Malthusian agriculture and others are still in the throes of the process. TheMeso-Industrial Age, as it might be called, is the period during which the rest of the world,principally the countries of sub-Saharan Africa and the Middle East, makes the evolutionarytransition to the social behaviors needed to support modern economies. No doubt the process requiressome adaptation and a change in institutions. But given the speed of evolution and the rapidity ofcultural change in today’s world, the Meso-Industrial Age may be over in far fewer generations thanmight be expected.

It is now time to consider a special population that for many centuries lacked a homeland of itsown. Jewish culture is as distinctive as that of many other groups but, because of its particular nature,a strong case can be made that in important respects its culture has genetic roots.

I

8

JEWISH ADAPTATIONS

Surely . . . Judaism is more than the history of anti-semitism. Surely Jews deserve to be defined—and are infact defined, by others as well as by themselves—by those qualities of faith, lineage, sacred texts and moralteachings that have enabled them to endure through centuries of persecution.

—GERTRUDE HIMMELFARB1

n many spheres of life, Jews have made contributions that are far larger than might be expectedfrom their numbers. Jews constitute 0.2% of the world’s population, but won 14% of NobelPrizes in the first half of the 20th century, despite social discrimination and the Holocaust, and29% in the second. As of 2007, Jews had won an amazing 32% of Nobel Prizes awarded in the

21st century.2Jews have excelled not only in science but also in music (Mendelssohn, Mahler, Schoenberg), in

painting (Pissarro, Modigliani, Rothko), and in philosophy (Maimonides, Bergson, Wittgenstein).Jewish authors have won the Nobel Prize in Literature for writing in English, French, German,Russian, Polish, Hungarian, Yiddish and Hebrew.3

Such achievement requires an explanation, and the best and simplest is that Jews have adaptedgenetically to a way of life that requires higher than usual cognitive capacity. People are highlyimitative, and if the Jewish advantage were purely cultural, such as hectoring mothers or a specialdevotion to education, there would be little to prevent others from copying it. Instead, given the newrecognition of human evolution in the historical past, it is more likely that Jewish intellectualachievement has emerged from some pressure in their special history. Just as races have evolved inthe recent past, ethnicities within races will also evolve if they are reproductively isolated to someextent from their host population, whether by geography or religion. The adaptation of Jews to aspecial cognitive niche, if indeed this has been an evolutionary process, as is argued below,represents a striking example of natural selection’s ability to change a human population in just a fewcenturies.

Until the era of rapid DNA sequencing, it could be surmised that Jews were a distinct populationbecause of religious laws that frowned on marriage outside Judaism. But no one knew for certainbecause in the absence of genetic evidence it was impossible to estimate the amount of intermarriagethat might nevertheless have occurred throughout history. DNA analysis shows that Jews are adefinable set of populations and that Ashkenazi Jews, at least, can be distinguished genetically fromother Europeans. With each Jewish community, there has been some intermarriage with localpopulations but at a very slow rate. This neatly explains the observation by Jewish anthropologists

that Jews from all over the world resemble one another yet also resemble their host populations.The basis of the common resemblance is that Jews originated in Israel and carry shared

inheritance from the Semitic population of the region. As recently as 3,000 years ago, a date thatmarks the probable beginning of the Jewish religion, Jews were no different from anyone else: theywere part of the general Near East population from which today’s Arabs, Turks and Armenians arealso descended. But as soon as their religion started forbidding members to marry nonmembers, theJewish population would have entered into reproductive isolation, much as if it had been placed on aremote island. Some large degree of reproductive isolation is the necessary condition for apopulation to take its own evolutionary path.

As to European Jews, or Ashkenazim, genetics show that there has been a 5% to 8% admixturewith Europeans since the founding of the Ashkenazi population in about 900 AD, which is equivalentto 0.05% per generation.4 Researchers using a SNP chip that tests the genome at 550,000 sites reportthat they were able to distinguish with complete accuracy between Ashkenazim and non-JewishEuropeans. This is a test applicable to populations, not individuals, since it depends on seeing howindividuals cluster together in terms of statistical differences in their genome sequences. Still, itshows that Ashkenazim are a distinctive population and therefore could have been subjected to forcesof natural selection different from those acting on other Europeans.

Ashkenazim probably differ genetically from other Europeans because of the Near Easterncomponent in their ancestry. “It is clear that the genomes of individuals with full Ashkenazi Jewishancestry carry an unambiguous signature of their Jewish heritage, and this seems more likely to be dueto their specific Middle Eastern ancestry than to inbreeding,” the researchers say.5

The rate of admixture with host populations has probably been similar among the other two mainJewish populations. These are the Sephardim and the Oriental Jews or Mizrahim. The Sephardim areJews who had long lived in Spain and Portugal but were expelled from those countries in 1492 and1497. They then dispersed around the Mediterranean to places like North Africa and the Ottomanempire. Many Sephardim also settled in Holland. Oriental Jews are those who have long lived inArab countries and Iran. The origin of the Sephardim is still obscure but there are genetic hints thatboth they and the Ashkenazim may be offshoots of the large Jewish community that lived in Romeduring the early Roman empire.

On genetic maps of the world’s population, the three Jewish groups cluster together, sandwichedbetween the Middle Eastern populations with whom they share joint ancestry and the Europeanpopulations with which the Ashkenazim and Sephardim are admixed.

Given this degree of genetic separation, it is perfectly possible for Jewish populations to havefollowed a slightly different evolutionary path from Europeans as they adapted to the specialcircumstances of their history and developed unusual cognitive abilities.

Yet the idea that there could be meaningful genetic differences between human groups is fiercelyresisted by many researchers. They cling to the idea that the mind is a blank slate on which onlyculture, not genetics, can write, and dismiss the possibility that evolution could have effected anyrecent change in the human mind. They reject the proposal that any human behavior, let aloneintelligence, has a genetic basis. They make accusations of racism against anyone who suggests thatcognitive capacities might differ between human population groups. All these positions are shaped byleftist and Marxist political dogma, not by science. Nonetheless, most scholars will not enter thisterritory from lively fear of being demonized by their fellow academics.

A more substantive objection to exploring this issue has to do with sensitivities of the Jewishcommunity. As with the Chinese immigrant communities in Asia, hard work and success has too oftenprovoked the envy and enmity of their host populations, leading to discrimination, expulsions andmassacres. Discussion of Jewish intelligence carries the risk of stirring up hostility. But the days ofpogroms are past, and to ignore every difficult subject would serve only the forces of obscurantism.

The only serious recent attempt by researchers to delve into the links between Jewish geneticsand intelligence is an extended essay by Gregory Cochran, Jason Hardy and Henry Harpending of theUniversity of Utah. Their report was submitted to several journal editors in the United States, all ofwhom said it was fascinating but that they could not publish it. The authors eventually securedpublication in England, in the Journal of Biosocial Science.6

The essence of the Utah team’s argument is to assert a causal connection between two unusual andotherwise unexplained facts. The first is that Ashkenazi Jews, in addition to their culturalachievements, have a high IQ—generally measured at between 110 and 115, which is the highestaverage of any ethnic group. The second is that Ashkenazim have a strange pattern of so-calledMendelian diseases, those that are caused by a mutation in a single gene.

The Utah researchers note first that Ashkenazi IQ, besides being high, has an unusual structure. Ofthe components of IQ tests, Ashkenazim do well on verbal and mathematical questions but scorelower than average on visuospatial questions. In most people, these two kinds of ability are highlycorrelated. This suggests that some specific force has been at work in shaping the nature of Ashkenaziintelligence, as if the population were being adapted not to hunting, which requires excellentvisuospatial skills, but to more urban occupations served by the ability to manipulate words andnumerals.

So it’s striking to find that Ashkenazim, almost from the moment their appearance in Europe wasfirst recorded, around 900 AD, were heavily engaged in moneylending. This was the principaloccupation of Jews in England, France and Germany. The trade required a variety of high level skills,including the ability to read and write contracts and to do arithmetic. Literacy was a rare ability inmedieval Europe. As late as 1500, only 10% of the population of most European countries wasliterate, whereas almost all Jews were.7

As for arithmetic, it may be simple enough with the Arabic numerals in use today. But Arabicnumerals did not become widespread in Europe until the mid-16th century. Before that, people usedRoman numerals, a notation system that has no zero. Calculating interest rates and currency swapswithout the use of zero is not a straightforward computation.

There were no banks in those days, and moneylenders were essential for those who wished to buyon credit or engage in long-distance trade. The moneylender had to assess the creditworthiness ofborrowers, appraise collateral, understand local contract law, and stay on good terms with theauthorities who would enforce it. For those engaged in long-distance trade, in which physical transferof money was generally avoided because of the danger, it was necessary to arrange credit withreliable partners in faraway cities.

So it’s easy enough to accept the Utah team’s first premise, that Ashkenazi Jews of the MiddleAges were engaged in a cognitively demanding occupation. The second point is that this occupation,though highly risky, was also highly rewarding. In all the European countries in which they settled,Jews enjoyed high standards of living. Between 1239 and 1260, taxes paid by Jews contributedbetween one sixth and one fifth of royal revenues, even though Jews constituted 0.01% of the

population. In 1241 Jews in Germany paid 12% of the entire imperial tax revenue.8

The wealth was important because it enabled Jews to secure a considerable degree ofreproductive success. Before the Industrial Revolution and the escape from the Malthusian trap, therich had more surviving children, being able to provide better nutrition and warmer houses. TheAshkenazi population had grown from almost nothing in 900 AD to about 500,000 people by 1500 AD,and had reached 14.3 million by 1939.9

From about 900 AD to 1700 AD, Ashkenazim were concentrated in a few professions, notablymoneylending and later tax farming (give the prince his money up front, then extract the taxes due fromhis subjects). Because of the strong heritability of intelligence, the Utah team calculates that 20generations, a mere 500 years, would be sufficient for Ashkenazim to have developed an extra 16points of IQ above that of Europeans. The Utah team assumes that the heritability of intelligence is0.8, meaning that 80% of the variance, the spread between high and low values in a population, is dueto genetics. If the parents of each generation have an IQ of just 1 point above the mean, then averageIQ increases by 0.8% per generation. If the average human generation time in the Middle Ages was25 years, then in 20 human generations, or 500 years, Ashkenazi IQ would increase by 20 × 0.8 = 16IQ points.

There were of course Christian moneylenders who required the same cognitive skills asAshkenazim. But the Christians married into a much larger community that included people in manyother occupations. Natural selection may have been raising the intelligence of urban populations ingeneral during the Middle Ages but exerted a much stronger effect on the smaller Jewish population.This was because any intelligence-enhancing genes that arose in a family in the general populationwould be diluted in the next generation, but could accumulate in the Jewish community becausemarriage to outsiders was deterred. This selective effect could not operate on Oriental Jews—thoseunder Muslim rule—because their rulers for the most part confined them to unpopular occupationslike tanning or butchery which required no particular intellectual skills. Oriental Jews and Sephardimare not overrepresented in cognitively demanding occupations and both have IQs comparable toEuropeans, the Utah team says.

The Utah researchers give short shrift to the other explanations that have been proposed forenhanced Jewish intelligence. One is that the series of massacres and expulsions that began at the timeof the First Crusade in 1096 constituted a selective effect that only the more intelligent were able tosurvive. But the massacres and expulsions affected the whole Ashkenazi population and seem unlikelyto have selected the more intelligent nearly as precisely as did the skills required for moneylending.

Jewish folklore holds that marriages between the children of rabbis and rich merchants were thedriver of enhanced intelligence. Talmudic academies, writes the anthropologist Melvin Konner,“culled the best minds in every generation of Jews for more than a thousand years. Rising stars amongthese bright young men would board with successful merchants, and matches would be made betweenthem and the merchants’ daughters. Thus the smartest, most studious boys would join the wealthiestfamilies.” 10

Without any data as to how often such matches were made, this seems more like a scholar’sfantasy than a common arrangement. Rich merchants may have been more likely to see anothermerchant’s son as a more promising son-in-law than a poor rabbinical student. But even if suchmarriages did sometimes occur, there were not enough rabbis in the population—a mere 1%—tomake a genetically significant difference, the Utah team says.

The Utah researchers make a plausible enough general case that the selective pressure from acognitively demanding occupational niche would have selected for higher intelligence amongAshkenazim. They then go on to identify what they believe are the causative genes. Their proposals, ifconfirmed, would give specific plausibility to the general argument but, if false, would not bring itdown.

The genetic argument concerns the mutations that cause Mendelian diseases. Mendelian, orsimple, diseases are those that result from a mutation that disables a single gene, as opposed tocomplex diseases like cancer or diabetes, which are the product of several causative variant genes.

Every population has its own pattern of Mendelian diseases. Among Jews, some Mendelianmutations, like familial Mediterranean fever, are very ancient, being shared with other MiddleEastern populations like Turks and Druze, while others are found among only Ashkenazim orSephardim and so must have occurred after the two populations separated.

The Utah team’s analysis focuses on a group of four Mendelian diseases that occur in Ashkenazimand affect an obscure biochemical function, the storage of fats known as sphingolipids. The fourdiseases are known as Tay-Sachs, Gaucher’s, Niemann-Pick and mucolipidosis type IV.

Inheriting a single copy of any of these variant genes does no great harm: the good copy inheritedfrom the other parent compensates for the defective allele. But inheriting a double dose of the variantalleles can cause serious impairment in the case of Gaucher’s and is lethal in the case of the otherthree diseases.

The variant genes that cause the four diseases are found in relatively high proportions in theAshkenazi population. When a version of gene is more common than expected, geneticists usuallyassume one of two causes. One is natural selection and the other is the influence known as a foundereffect.

Why should natural selection favor a variant gene associated with a lethal disease? This canhappen when the variant, though lethal in a double dose, confers some advantage when inherited fromonly one parent. A well-known example is that of sickle-cell anemia. A person with one copy of thevariant gene is protected from malaria, but those who inherit two copies suffer from a serious blooddisease. The allele will be favored by natural selection because the many single-allele carriers, whoare protected from malaria, far outnumber the carriers of two alleles, who die or suffer impairment.

The other reason why a variant gene can be more common than expected is that it happened tooccur at high frequency in a small population that later expanded. Any rare mutation carried by one ofthe population’s founders will be inherited by his or her descendants and attain a higher frequency inthat population than in most others, a situation known as a founder effect.

The geneticist Neil Risch has concluded that the Ashkenazi Jewish mutations are founder effectsthat arose around 1,000 years ago. Since the mutations all arose at the same time, they must have thesame cause, and that must be a founder effect, Risch argues, because such a variety of mutations isunlikely to offer any specific advantage that natural selection might favor.11

But this argument is neatly turned around by the Utah team. They agree that the Ashkenazimutations arose within the past 1,000 years but argue that the mutations were indeed all favored bynatural selection at the same time because they all promote intelligence.

If the founder effect argument is rejected, a plausible reason for the commonness of AshkenaziMendelian mutations would be that they protect against some serious disease. But no such protectiveeffect has yet been detected. In any case, Ashkenazi Jews and the European populations they lived

among suffered from the same diseases, yet there is no similar pattern of mutations in Europeans.The only significant difference in the Ashkenazi way of life was that they worked in cognitively

demanding occupations, the Utah team argues, so this must be the selective pressure that drove theAshkenazi Mendelian mutations to such relatively high levels.

Another reason for assuming natural selection is at work, rather than a founder effect, is that someof the Ashkenazi mutations occur in clusters. This is highly unusual because mutations strike atrandom throughout the genome so should not be concentrated in genes that all have the same function.One set of Ashkenazi mutations occurs in the cluster of genes that controls the sphingolipid storagepathway mentioned above. For four mutations to be found in a specific pathway is a strong indicationof natural selection. The Utah team points to experimental evidence, though there is not very much ofit, suggesting that disruption of sphingolipid storage induces neurons to make more connections thanusual.

A second cluster of four mutations is found in a DNA repair pathway. Two of the mutations occurin the BRCA1 and BRCA2 genes and are associated with breast and ovarian cancer. The other twomutations cause the diseases Fanconi’s anemia type C and Bloom syndrome. It is hard to see howdisruptions of DNA repair systems could be beneficial in any context, especially in the case of thetwo BRCA mutations, which carry risk even when an individual has a single copy of the mutatedgene. The Utah team notes that BRCA1 can limit cell proliferation in neuronal stem cells in theembryo and adult, so that impairing the gene could allow extra brain cells to be generated. Theysuggest there may be similar advantages, yet to be discovered, in the other DNA repair mutations.

Though the exact role of the Mendelian mutations in promoting intelligence has yet to be clarified,they are strikingly common among Ashkenazim. Some 15% of Ashkenazi Jews carry one of thesphingolipid or DNA repair mutations, and 60% carry either these or one of the other Mendeliandisease mutations special to Ashkenazim. As already noted, the mutations are harmless wheninherited from just one parent. The Utah team’s explanation seems the best so far for this strangepattern of mutations, and in particular for those that exist in clusters. Moreover, it is a great virtue in ascientific hypothesis to be easily testable, as the Utah team’s theory is. The theory implies that peoplecarrying one of the Ashkenazic mutations will be found to have higher IQ scores, on average, thanpeople who do not. Anyone with access to a population of Ashkenazim could test the prediction thathigh IQ is associated with the Ashkenazic mutations. Strange to say, no one has yet done so or, if theyhave, they have not published their findings.

Without being able to test a living population, the Utah team obtained indirect evidence thatGaucher’s disease raises IQ. They found that of 255 working age patients at a Gaucher’s clinic inIsrael, one third were in fields like science, accountancy or medicine, which require high IQs, a fargreater proportion than in the population as a whole.

Advantages of Literacy

A possible weakness of the Utah team’s proposal is the assertion that enhanced cognitive capacity isconfined to the Ashkenazic branch of the Jewish population. Sephardim have given the worldSpinoza, Disraeli, Ricardo and many other distinguished individuals. It is hard to find specificmeasurements of Sephardic IQ, and the Utah team offer none in their article. Measurements of IQ inIsrael report that Ashkenazi IQ is higher than that of non-Ashkenazim, but the latter group includesOriental Jews as well as Sephardim. The Utah team focuses on Ashkenazi Jews because theMendelian mutations found in Ashkenazim seem to have originated around 1000 AD, after Ashkenazimand Sephardim became separate populations. But even if the Utah team’s thesis has merit, there is noreason why Jews should not have enjoyed special cognitive capacities from much earlier in theirhistory; if so, these traits could later have been enhanced among Ashkenazim in the manner the Utahteam describes.

A new perspective on Jewish history has recently been developed by two economic historians,Maristella Botticini and Zvi Eckstein. Botticini specializes in medieval contracts and marriagemarkets and teaches at Bocconi University in Milan. Eckstein is a distinguished economist who hasserved as deputy governor of the Bank of Israel. Their interest in Jewish history is focused onpopulation numbers and occupation. They allude hardly at all to intelligence or genetics, yet theireconomic history makes abundantly clear how selection pressures could have acted on the Jewishpopulation so as to enhance cognitive capacity.

The widely held conventional explanation for Jewish occupational history is that Jews wereforbidden by their Christian host nations to own land and drifted into moneylending because it wasthe only profession open to them. Because of frequent expulsions and persecutions, according to thisview, Jewish communities were dispersed in towns all over Europe and the Mediterranean world.

Botticini and Eckstein reject this explanation, arguing with a wealth of historical detail that Jewswere not forced into moneylending but rather chose it because it was so profitable, and that theygenerally dispersed not because of persecution but because there were jobs for only so manymoneylenders in each town.

But how did Jews come to choose this unusual occupation? Botticini and Eckstein develop asimple but forceful explanation that goes back to the beginnings of rabbinical Judaism in the 1stcentury AD.

Before the rabbinical era, Israelite religion was focused on the temple in Jerusalem and oncopious animal sacrifices. Its leaders promoted three major insurrections against Roman rule, the firstof which culminated in the destruction of the Jerusalem temple in 70 AD. The loss of the templestrengthened the position of the Pharisees, one of several sects, and led them to develop a quitedifferent version of Judaism in which the temple and animal sacrifice were replaced as centralcomponents of the religion by study of the Torah.

The rabbinical form of Judaism that emerged from this movement emphasized literacy and theskills to read and interpret the Torah. Even before the destruction of the temple, the Pharisee highpriest Joshua ben Gamla issued a requirement in 63 or 65 AD that every Jewish father should send hissons to school at age six or seven. The goal of the Pharisees was universal male literacy so thateveryone could understand and obey Jewish laws. Between 200 and 600 AD, this goal was largely

attained, as Judaism became transformed into a religion based on study of the Torah (the first fivebooks of the Bible) and the Talmud (a compendium of rabbinic commentaries).

This remarkable educational reform was not accomplished without difficulty. Most Jews at thetime earned their living by farming, as did everyone else. It was expensive for farmers to educatetheir sons and the education had no practical value. Many seem to have been unwilling to do sobecause the Talmud is full of imprecations against the ammei ha-aretz, which in Talmudic usagemeans boorish country folk who refuse to educate their children. Fathers are advised on no account tolet their daughters marry the untutored sons of the ammei ha-aretz.

The scorned country folk could escape this hectoring without totally abandoning Judaism. Theycould switch to a form of Judaism Lite developed by a diaspora Jew, one that did not require literacyor study of the Torah and was growing in popularity throughout this period. The diaspora Jew wasPaul of Tarsus, and Christianity, the religion he developed, seamlessly wraps Judaism around themystery cult creed of an agricultural vegetation god who dies in the fall and is resurrected in thespring.12

As evidence that many Jews did indeed convert to Christianity, Botticini and Eckstein citeestimates showing that the Jewish population declined dramatically from around 5.5 million in 65 ADto a mere 1.2 million in 650 AD. There is little else to account for such a dramatic decline other than ahigh rate of conversion away from Judaism.

Botticini and Eckstein make no mention of the genetic forces that would have been brought intoplay by such a conversion. But if Jews who lacked the ability or commitment to become literate wereshed from the community generation after generation, the propensity for literacy of those remainingwould steadily rise. The rabbinical requirement for universal male literacy may thus have been thefirst step toward a genetic enhancement of Jewish cognitive capacity. A second step was to comelater, when the literacy was put to great practical effect.

By 650 AD, Jews had almost entirely disappeared from regions where Christianity was strong,including Syria, Lebanon, Egypt and even Israel itself. The center of the Jewish world shifted to Iraqand Persia. There was also a shift in Jewish occupations. Jews abandoned farming and moved totowns, where they entered trade and commercial activities or became shopkeepers and artisans.

After the establishment of the Abbasid caliphate in 750 AD, Jews migrated to the newlyprospering towns and cities. By 900 AD, almost all Jews were engaged in urban occupations, dealingwith crafts, trade, moneylending and medicine. Why did Jews choose professions in these particularfields? Common belief is they were forbidden to own land and denied entry to certain crafts. Botticiniand Eckstein say there is little or no evidence for such prohibitions. Jews concentrated in professionslike trade and moneylending, they argue, for a simple reason. In a world where most people wereilliterate, the literacy of almost all Jews gave them a decided advantage in any occupation thatrequired reading contracts or keeping accounts.

Jews enjoyed another practical benefit conferred by their religion. Jewish communities weresubject to law, as laid out in the Talmud, and rabbinic courts oversaw contract enforcement anddisputes. Because of the presence of Jewish communities in many cities of Europe and the Near East,Jews had access to a natural trading network of their coreligionists. Both the network and the disputeresolution mechanism were unusual and gave Jews a special advantage in long-distance commerce.

As trade and urbanization started to flourish in the Muslim world under the Abbasids, the “higherliteracy of the Jewish people,” Botticini and Eckstein write, “gave the Jews a comparative advantage

over non-Jews in crafts, trade, commerce and money-lending.” 13

The sack of Baghdad by the Mongols in 1258 destroyed the political and cultural center of theAbbasid empire, and large regions of Iraq and Persia became depopulated. The population center ofthe Jewish community now shifted to Europe, where Jews increasingly specialized in moneylending.

This occupational pattern had a profound demographic consequence. Because moneylending wasso profitable, despite its high risks, Jews could afford to support large families and, like otherwealthy people, could ensure that more of their children survived to adulthood. After the devastationof the Jewish communities in Iraq and Persia and the expulsion of European Jews from England,France and many regions of Germany, their total population fell to fewer than 1 million in 1500 AD.But propelled by their new wealth, the Jewish population started to increase rapidly and by 1939 hadreached 16.5 million globally.

From an evolutionary perspective, the population increase was the result of a successfuladaptation. Because of the requirement for literacy, Jews found themselves better able than non-Jewsto cope with the new cognitive demands of urban commerce. “Jews had the behavioral traitsconducive to success in a capitalist society,” writes the historian Jerry Z. Muller. “They enteredcommercializing societies with a stock of know-how from their families and communities about howmarkets work, about calculating profit and loss, about assessing and taking risks. Most important,though hardest to specify, Jews demonstrated a propensity for discovering new wants and to bringingunderused resources to market.” 14

Like Chinese immigrant communities, Jews have brought enormous benefits to the economies inwhich they worked. Unfortunately their success, like that of the immigrant Chinese, has in many caseselicited not gratitude but envy, followed by discrimination or murderous reprisals, a response thatreflects more strongly on the greed than the intelligence of their host populations.

From a glance at an Eskimo’s physique, it is easy to recognize an evolutionary process at workthat has molded the human form for better survival in an arctic environment. Populations that live athigh altitudes, like Tibetans, represent another adaptation to extreme environments; in this case, thechanges in blood cell regulation are less visible but have been identified genetically. The adaptationof Jews to capitalism is another such evolutionary process, though harder to recognize because theniche to which Jews are adapted is one that has required a behavioral change, not a physical one.

Because of this adaptation, the Jewish population includes proportionately more individuals ofhigher cognitive capacity than do most others. It thus punches above its weight in endeavors requiringhigh intelligence. Traits like intelligence are distributed in the shape of a bell, with large numbers ofpeople having the average value and progressively fewer as one moves toward either the higher orlower extreme. It takes only a slight upward shift in the average value to yield significantly more atthe upper extreme. Average northern European IQ is 100, by definition, and 4 people per 1,000 insuch a population would be expected to have IQs above 140 points. But among Ashkenazim, if theaverage IQ is taken as 110, then 23 Ashkenazim per 1,000 should exceed 140, the Utah teamcalculates, a proportion almost six times greater than that in northern Europe. This helps explain whythe Jewish population, despite its small size, has produced so many Nobel Prize winners and othersof intellectual distinction.

I

9

THE RISE OF THE WEST

Little by little all the non-western peoples of the earth found it necessary to do something drastic about theintrusive Europeans with their restless, disturbing ways. The rise of the West to this position of dominance allround the globe is, indeed, the main theme of modern world history.

—WILLIAM MCNEILL1

Past, present and future, the story of military dynamism in the world is ultimately an investigation into theprowess of Western arms.

—VICTOR DAVIS HANSON2

Yet any history of the world’s civilizations that underplays the degree of their gradual subordination to theWest after 1500 is missing the essential point—the thing most in need of explanation. The rise of the West is,quite simply, the pre-eminent historical phenomenon of the second half of the second millennium after Christ.It is the story at the very heart of modern history. It is perhaps the most challenging riddle historians have tosolve.

—NIALL FERGUSON3

n 1608 Hans Lippershey, a spectacle maker in the Dutch town of Middelburg, invented thetelescope. Within a few decades, telescopes had been introduced from Europe to China, to theMughal empire in India and to the Ottoman empire. All four civilizations were thus on an equalfooting in terms of possessing this powerful new instrument with its latent power for observing

the universe and deducing the laws of planetary motion.There are few controlled experiments in history, but the historian of science Toby Huff has

discovered one in the way that the telescope was received and used in the 17th century. The reactionsof the four civilizations to this powerful new instrument bear on the very different kinds of societythat each had developed.

In Europe the telescope was turned at once toward the heavens. Galileo, hearing a description ofLippershey’s device, immediately set to building telescopes of his own. He was first to observe themoons of Jupiter, and he used the fact of Jupiter’s satellites as empirical evidence in favor ofCopernicus’s then disputed notion that the planets, including the Earth, were satellites of the sun.Galileo’s argument that the Earth revolved around the sun brought him into conflict with the church’sbelief that the Earth cannot move. In 1633 he was forced to recant by the Inquisition and placed underhouse arrest for the rest of his life.

But Europe was not monolithic, and the Inquisition was powerless to suppress the ideas ofCopernicus and Galileo in Protestant countries. What Galileo had started was carried forward by

Kepler and Newton. The momentum of the Scientific Revolution scarcely faltered.In the Muslim world, the telescope quickly reached the Mughal empire in India. One was

presented in 1616 by the British ambassador to the court of the emperor Jahangir, and many morearrived a year later. The Mughals knew a lot about astronomy, but their interest in it was confined tomatters of the calendar. A revised calendar was presented to the Mughal emperor Shah Jahan in 1628,but the scholar who prepared it based it on the Ptolemaic system (which assumes that the sun revolvesaround an immobile Earth).

Given this extensive familiarity with astronomy, Mughal scholars might have been expected to usethe telescope to explore the heavens. But the designers of astronomical instruments in the Mughalempire did not make telescopes, and the scholars created no demand for them. “In the end, no Mughalscholars undertook to use the telescope for astronomical purposes in the seventeenth century,” Huffreports.4

The telescope fared no better in the other Islamic empire of the time. Telescopes had reachedIstanbul by at least 1626 and were quickly incorporated into the Ottoman navy. But despite Muslimeminence in optics in the 14th century, scholars in the Ottoman empire showed no particular interestin the telescope. They were content with the Ptolemaic view of the universe and made no effort totranslate the works of Galileo, Copernicus or Kepler. “No new observatories were built, noimproved telescopes were manufactured and no cosmological debates about what the telescoperevealed in the heavens have been reported,” Huff concludes.5

Outside of Europe, the most promising new users of the telescope were in China, whosegovernment had a keen interest in astronomy. Moreover, there was an unusual but vigorousmechanism for pumping the new European astronomical discoveries into China in the form of theJesuit mission there. The Jesuits figured they had a better chance of converting the Chinese toChristianity if they could show that European astronomy provided more accurate calculations of thecelestial events in which the Chinese were interested. Through the Jesuits’ efforts, the Chinesecertainly knew of the telescope by 1626, and the emperor probably received a telescope fromCardinal Borromeo of Milan as early as 1618.

The Jesuits invested significant talent in their mission, which was founded by Matteo Ricci, atrained mathematician who also spoke Chinese. Ricci, who died in 1610, and his successors importedthe latest European books on math and astronomy and diligently trained Chinese astronomers, who setabout reforming the calendar. One of the Jesuits, Adam Schall von Bell, even became head of theChinese Bureau of Mathematics and Astronomy.

The Jesuits and their Chinese followers several times arranged prediction challenges betweenthemselves and Chinese astronomers following traditional methods, which the Jesuits always won.The Chinese knew, for instance, that there would be a solar eclipse on June 21, 1629, and theemperor asked both sides to submit the day before their predictions of its exact time and duration. Thetraditional astronomers predicted the eclipse would start at 10:30 AM and last for two hours. Insteadit began at 11:30 AM and lasted two minutes, exactly as the Jesuits had calculated.

But these computational victories did not solve the Jesuits’ problem. The Chinese had littlecuriosity about astronomy itself. Rather, they were interested in divination, in forecasting propitiousdays for certain events, and astronomy was merely a means to this end. Thus the astronomical bureauwas a small unit within the Ministry of Rites. The Jesuits doubted how far they should get into thebusiness of astrological prediction, but their program of converting the Chinese through astronomical

excellence compelled them to take the plunge anyway. This led them into confrontation with Chineseofficials and to being denounced as foreigners who were interfering in Chinese affairs. In 1661,Schall and the other Jesuits were bound with thick iron chains and thrown into jail. Schall wassentenced to be executed by dismemberment, and only an earthquake that occurred the next dayprompted his release.

The puzzle is that throughout this period the Chinese made no improvements on the telescope. Nordid they show any sustained interest in the ferment of European ideas about the theoretical structure ofthe universe, despite being plied by the Jesuits with the latest European research. Chineseastronomers had behind them a centuries-old tradition of astronomical observation. But it wasembedded in a Chinese cosmological system that they were reluctant to abandon. Their latentxenophobia also supported resistance to new ideas. “It is better to have no good astronomy than tohave Westerners in China,” wrote the anti-Christian scholar Yang Guangxian.6

Both China and the Muslim world suffered from a “deficit of curiosity” about the natural world,Huff says, which he attributes to their educational systems. But the differences between Europeansocieties and the others went considerably beyond education and scientific curiosity. The reception ofthe telescope shows that by the early 17th century, fundamental differences had already emerged inthe social behavior of the four civilizations and in the institutions that embodied it. Europeansocieties were innovative, outward looking, keen to develop and apply new knowledge, andsufficiently open and pluralistic to prevent the old order from suppressing the new. Those of Chinaand the Islamic world were still entrammeled in traditional religious structures and too subservient tohierarchy to support freethinking and innovation.

The Dynamism of the West

The trends in the 17th century illumined by Huff’s telescope experiment have continued to the presentday with surprisingly little change. Four hundred years later, European societies are still more openand innovative than others. Islamic societies are still inward looking, traditional and hostile topluralism. An authoritarian regime still rules China, suppresses all organized opposition and inhibitsthe free flow of ideas and information. The steadiness of these salient trends is a strong indication,though indeed not proof, that evolutionary forces have shaped the basic nature of these societies andtheir institutions.

Because its societies are open and innovative, the West has come to achieve a surprising degreeof dominance in many spheres, despite the fact that its methods and knowledge have long been anopen book from which all others may copy. Most of the world is now integrated into the Westerneconomic system. But Japan and China, two of its chief economic rivals, show few signs of becomingbetter innovators. Most of the world’s most successful corporations are still found in the West.Americans and Europeans still dominate most fields of scientific research and collect most NobelPrizes.

The West continues to lead in military power. Its preeminence has not been uniform. Japandefeated the Russian fleet at the battle of Tsushima in 1905 and seized the East Asian holdings ofEuropean colonial powers in the Second World War. China battled the United States to a draw in theKorean War, and the United States did not prevail in Vietnam. European powers have withdrawnfrom many colonized countries after the cost of holding them became prohibitive. But Western forcehas remained essentially unchallenged since it withstood the threat of Ottoman invasion in the 17thcentury. For centuries, the most serious adversaries of Western powers have been other Westernnations.

Western science, a driver of technology, still holds a commanding lead over that of othercountries. Despite the expectation that Japanese science would become formidable in the wake of itsmodernization, this flowering has failed to take place. And despite its heavy investment in scientificresearch, there is no guarantee that by mere force of numbers China can become a major scientificpower. Science is essentially subversive in that it requires, at least in its great advances, the topplingof accepted theories and their replacement with better ones. East Asian societies tend to place highvalue on conformity and respect for superiors, which is not fertile ground for science to flourish.

Throughout the world, Western medicine has proven more effective than the traditional kind.Western music, art and film are generally more creative than the tradition-bound artistic cultures ofthe East, and the openness of Western societies is regarded by many as more appealing. It would beinvalid to ascribe any particular virtue to Europeans as individuals—they are little different fromanyone else. But European social organization and especially its institutions have by severalsignificant yardsticks proved more productive and innovative than those of other races. What thenexplains the rise and continued success of the West?

Geographic Determinism

One explanation for the rise of the West is geographical. The geographer Jared Diamond is the mostrecent exponent of the idea. In his well-known book Guns, Germs, and Steel, he argues that the Westis more powerful than others simply because it got a head start by enjoying more favorable conditionsfor agriculture. The nature of the people themselves, or their societies, have nothing to do with it, inhis view. Everything in human history was determined by geographical features, such as the plant andanimal species available for domestication or the plagues endemic in one population but not another.

Despite the popularity of Diamond’s book, there are several serious gaps in its argument. One isits anti-evolutionary assumption that only geography matters, not genes. His book, Diamond writes,can be summarized in a single sentence: “History followed different courses for different peoplesbecause of differences among peoples’ environments, not because of biological differences amongpeoples themselves.” 7 Geographic determinism, however, is as absurd a position as geneticdeterminism, given that evolution is about the interaction between the two.

Diamond’s book is constructed as an answer to the question he was asked by a New Guineatribesman as to why Western civilization produced so many more material goods than New Guineansociety. Diamond gives no weight to such developments as the rise of modern science, the IndustrialRevolution and the economic institutions through which Europeans at last escaped the Malthusiantrap. Indeed, when Europeans brought their economic methods to Australia, for instance, they werequickly able to create and operate a European economy. Aborigines, the native Australian population,were still in the Paleolithic Age when Europeans arrived and showed no signs of developing anymore advanced material culture.

If in the same environment, that of Australia, one population can operate a highly productiveeconomy and another cannot, surely it cannot be the environment that is decisive, as Diamond asserts,but rather some critical difference in the nature of the two people and their societies.

Diamond himself raises this counterargument, but only to dismiss it as “loathsome” and “racist,” astratagem that spares him the trouble of having to address its merits. While demonizing the opponentsof one’s views is often effective in the academic sandbox, it is not automatically racist to considerracial categories as a possible explanatory factor. Diamond himself does so when it suits his purpose.He states that “natural selection promoting genes for intelligence has probably been far more ruthlessin New Guinea than in more densely populated, politically complex societies. . . . In mental ability,New Guineans are probably genetically superior to Westerners.” 8 There is no evidence that thisunlikely conjecture is true.9

Equally strange is his assertion that intelligence is more likely to be favored in Stone Agesocieties than in modern ones. Intelligence can be more highly rewarded in modern societies becauseit is in far greater demand, and the East Asians and Europeans who have built such societies do infact have higher IQ scores, which may mean higher intelligence, than people who live in tribal orhunter-gatherer societies.

Guns, Germs, and Steel has been widely popular, but the many readers who presumably skipover the oddity of its counterfactual statements are missing an important clue to the nature ofDiamond’s book. It is driven by ideology, not science. The pretty arguments about the availability ofdomesticable species or the spread of disease are not dispassionate assessments of fact but are

harnessed to Diamond’s galloping horse of geographic determinism, itself designed to drag the readeraway from the idea that genes and evolution might have played any part in recent human history.

Geography and climate have undoubtedly been important, but not to the overwhelming degree thatDiamond suggests. The effects of geography are easiest to see in a negative sense, especially theirrole in holding back population-driven urbanization in regions of low population density, such asAfrica and Polynesia. Much harder to understand is how Europe and East Asia, lying on much thesame lines of latitude, were driven in the different directions that led to the West’s dominance.

If geography provides only a first cut at the answer, can economics provide a more detailedexplanation for the rise of the West? As recounted in chapter 7, economic historians have generallylooked to factors such as institutions and resources to explain the genesis of the Industrial Revolution.But many of the apparent conditions for success were present in China as well as England, givinglittle evident reason for the West’s preeminence. “Almost every element usually regarded byhistorians as a major contributory cause to the industrial revolution in north-western Europe was alsopresent in China,” concluded the historian Mark Elvin.10

Those who favor institutions as the key to the Industrial Revolution have emphasized England’sGlorious Revolution of 1688, which placed the sovereign firmly under the control of Parliament andrationalized economic incentives. But both the Glorious Revolution and the Industrial Revolution thatfollowed it were late developments in the rise of the West, the foundations of which historiansbelieve were laid much earlier.

In a recent essay seeking to explain the rise of the West, the historian Niall Ferguson cited sixinstitutions, the first of which he calls competition. By competition he means “a decentralization ofpolitical life, which created the launch-pad for both nation-states and capitalism.” 11 This is anotherway of saying that the West, broadly speaking, enjoyed open societies with competing institutions, asopposed to the unrelieved despotism of the East.

The open society made possible the other institutions Ferguson deems critical to the rise of theWest, such as the rule of law, including private property rights and the representation of propertyowners in a legislature; advances in science and medicine; and a growing economy fueled bytechnology and consumer demand.

“In the course of roughly 500 years,” Ferguson writes, “Western civilization rose to a position ofextraordinary dominance in the world. . . . Western science shifted the paradigms; others eitherfollowed or were left behind. Western systems of law and the political models derived from them,including democracy, displaced or defeated the non-Western alternatives. . . . Above all, the Westernmodel of industrial production and mass consumption left all alternative models of economicorganization floundering in its wake.” 12

A society with several different power centers is less likely than an autocracy to suppress newideas or to thwart innovation and entrepreneurship. Europe thus provided a more favorableenvironment than China for the emergence of science and medicine, and for the rise of capitalism. ButFerguson’s analysis boils down to the assertion that the West succeeded because it was an opensociety. This is true so far as it goes, but why did the West alone develop a society of this nature?“This openness of society, together with its inventiveness, becomes what is to be explained,” writesthe economic historian Eric Jones.13

How the West Arose

Some 50,000 years ago, a vast natural experiment was set in motion when modern humans dispersedacross the globe from their ancestral African homeland. In Africa, Australasia, East Asia, Europe andthe Americas, people developed very different kinds of society depending on the various challengesthey faced. For at least the past 500 years, for which detailed records exist, and probably for farlonger, these differences have been of an enduring nature.

Nature’s experiment, with at least five versions running in parallel for much of the time, has had acomplex outcome. What is clear is that from the same human clay, a wide variety of societies can bemolded. Australia serves as a kind of baseline. It was inhabited by immigrants from the Africanhomeland some 46,000 years ago. The descendants of these first inhabitants, according to theevidence of their DNA, managed to fend off all outsiders until the arrival of Europeans in the 17thcentury. At that time, their way of life had changed little. Australian aborigines still lived in tribalsocieties without towns or cities. Their technology differed little from that of the Paleolithic hunterswho reached Europe at the same time their ancestors arrived in Australia. During the 46,000 years oftheir isolation, they had invented neither the wheel nor the bow and arrow. They lived in a state ofperpetual warfare between neighboring tribes. Their most conspicuous cultural achievement was anintense religion, some of whose rituals lasted through day and night for months at a time. The leisureto pursue these elaborate devotions was earned by the aborigines’ ability to flourish in a near desertenvironment in which newcomers would have perished. But for lack of population growth anddemographic pressure, aboriginal tribes were never forced into the intense process of state formationand empire building that shaped other civilizations.

In Africa, population numbers were higher than in Australia, agriculture was quickly adopted andsettled societies developed. From these gradually emerged more complex societies, includingprimitive states. But because of low population density, these primitive states did not enter the phaseof political rivalry and sustained warfare from which empires emerged in Mesopotamia, the YellowRiver valley and, much later, in the Andean highlands. The population of Africa in 1500 was only 46million. The soil being mostly poor, there were few agricultural surpluses and so no incentive todevelop property rights. For lack of the wheel and navigable rivers, transport within Africa wasdifficult and trade was small scale. For lack of demographic pressure, African societies had littleincentive to develop the skills that trade stimulates, to accumulate capital, to develop occupationalspecialties or to generate modern societies. The phase of state and empire building had only justbegun when it was cut short by European colonization.

History in the Americas began only 15,000 years ago, when the first immigrants from Siberiatrekked across the then extant land bridge between Siberia and Alaska. Significant empires arose inMexico, Central America and the Andes. But the populations took many years to attain the criticaldensity for state formation. The Aztecs and Incas had made only a late and uncertain start towardmodern states and were already debilitated by internal weaknesses when the conquistadores arrivedon their doorstep.

Only in Eurasia did substantial states and empires emerge. More favorable climate and geographyallowed larger populations to develop. Under the transforming influences of trade and warfare,empires arose in China, India, the Near East and Europe.

It is hard to identify the influences that may have shaped the European population before about the5th century AD, when civil authority in the western half of the Roman empire collapsed. Ingeographical terms, Europe then consisted of a patchwork of cleared regions separated by forests,mountains or marshes. These cleared arable regions became the nucleus of new polities that began toemerge into states around 900 AD. But this defragmentation was a slow process. There were stillaround 1,000 political units in Europe by the 14th century. Nation-states began to develop in the 15thcentury. By 1900, Europe consisted of 25 states.14

China’s geography, by contrast, channeled the social behavior of its population in a very differentdirection. In the fertile plain between the Yangtze and Yellow rivers, population steadily grew and atan early date was forced into the usual winner-take-all competition between states. China was unifiedby 221 BC and remained an autocracy, subject to periodic raids from the powerful nomadic peoplesalong its northern borders.

“Any objective survey of the past 10,000 years of human history,” writes the anthropologist PeterFarb, “would show that during almost all of it, northern Europeans were an inferior barbarian race,living in squalor and ignorance, producing few cultural innovations.” 15 But during the early MiddleAges, a favorable combination of factors set the stage for Europeans to develop a particularlysuccessful form of social organization. These included a geography that favored the existence of anumber of independent states and made it hard for one to dominate all the rest; a population denseenough to encourage social stratification and trade; and an independent center of influence in the formof the church, which set limits on the power of local rulers. By 1200, Europe was still backwardcompared to China and the Islamic world, but it had institutions in place that were about to foster anunparalleled burst of innovation accompanied by the rise of science.

Origins of Modern Science

A distinctive feature of Western civilization is its creation of modern science. By delving into theroots of modern science, might one discover the essential factors that nudged European societies ontotheir special track?

A careful comparison of early science in Europe, the Islamic world and China has been made bythe science historian Toby Huff, whose telescope experiment is recounted above. To anyone whomight have surveyed the world in 1200 AD, modern science would have seemed most likely to arisenot in Europe but in the Islamic world or in China. The scientific works of ancient Greece weretranslated into Arabic in the 12th and 13th centuries. People writing in Arabic—who included Jews,Christians and Iranians as well as Arabs—made Arab science the most advanced in the world fromthe 8th until the 14th century. Scientists writing in Arabic led their fields in mathematics, astronomy,physics, optics and medicine. Arabs perfected trigonometry and spherical geometry.

China too would have seemed fertile ground for science. The three inventions cited by FrancisBacon in 1620 as the greatest known to man—the compass, gunpowder and the printing press—wereall Chinese in origin. Besides its technological inventiveness, China had a long history ofastronomical observation, a necessary base for understanding the mechanics of the sun’s planetarysystem.

Yet both Arab and Chinese science faltered for essentially similar reasons. Science is not theindependent action of lone individuals but a social activity, the work of a community of scholars whocheck, challenge and build on one another’s work. Science therefore needs social institutions, likeuniversities or research institutes, in which to thrive, and these have to be reasonably free ofintellectual constraints imposed by religious authorities or government.

In both the Islamic world and China, there proved to be no room for independent institutions. InIslam, there were madrasas, institutes for religious education, attached to mosques. But their primepurpose was to inculcate what were called Islamic sciences, the study of the Qur’an and Islamic law,and not foreign sciences, as the natural sciences were known. Much of ancient Greek philosophyconflicted with Qur’anic teaching and was excluded from study. Scholars who displeased religiousauthorities could find themselves abruptly silenced by a fatwa. The intellectual tradition of Islam, thatthe Qur’an and the sayings of Muhammad contained all science and law, created a hostileenvironment for all independent lines of thought.

Islamic rulers long kept challenges away by forbidding the printing press and squelchingtroublesome lines of inquiry. In Europe, interest in new knowledge was not confined to an elite butpervaded societies in which literacy was becoming more widespread. By 1500 there were 1,700printing presses distributed in 300 European cities in every country except Russia.16 In the Ottomanempire, a decree of Sultan Selim I specified the death penalty for anyone who even used a printingpress. Istanbul did not acquire a printing press until 1726 and the owners were allowed to publishonly a few titles before being closed down.

Religious authorities in Islamic countries disdained any source of knowledge other than theQur’an, and frequently exercised their power to suppress it. Institutes like the distinguished Maraghaobservatory in Iran, founded in 1259 AD, enjoyed only a brief lifetime. As late as 1580, anobservatory being built in Istanbul was torn down for religious reasons before it was even

completed.17

The economist Timur Kuran has recently argued that the Islamic world was held backeconomically largely because of rigidities in Islamic law regarding commerce. Corporations, forinstance, could be dissolved on the death of any partner if his heirs wanted immediate payment. “Insum, several self-enforcing elements of Islamic law—contracting provisions, inheritance system,marriage regulations—jointly contributed to the stagnation of the Middle East’s commercialinfrastructure,” he writes.18 But it is unconvincing to blame Islamic law; Europeans were faced withsimilar theologically based laws, such as those against usury, but they made the law accommodateitself to society’s larger purposes. In Islam the forces of modernity did not compel the Ottoman stateto modernize its legal system until the 19th century.

How is it, then, that Arabic science was so good in the 8th to 14th centuries, despite suchinhospitable conditions? The reason, Huff believes, is that in the early centuries of Muslim rule fewpeople had in fact converted to Islam. It was only when the pace of conversion picked up in the 10thcentury that Muslim majorities became commonplace, a dynamic “which probably had negativeconsequences for the pursuit of the natural sciences and intellectual life in general.” 19

China, though for different reasons, developed the same antipathy to modern science as did theIslamic world. One problem in China was the absence of any institutions independent of the emperor.There were no universities. Such academies as existed were essentially crammers for the imperialexamination system. Independent thinkers were not encouraged. When Hung-wu, the first emperor ofthe Ming dynasty, decided that scholars had let things get out of hand, he ordered the death penalty for68 degree holders and 2 students, and penal servitude for 70 degree holders and 12 students. Theproblem with Chinese science, Huff writes, was not that it was technically flawed, “but that Chineseauthorities neither created or tolerated independent institutions of higher learning within whichdisinterested scholars could pursue their insights.” 20 China, unlike the Islamic world, did not banprinting presses, but the books they produced were only for the elite.

Another impediment to independent thought was the stultifying education system, which consistedof rote memorization of the more than 500,000 characters that comprised the Confucian classics, andthe ability to write a stylized commentary on them. The imperial examination system, which began in124 BC, took its final form in 1368 AD and remained unchanged until 1905, deterring intellectualinnovation for a further five centuries.

That modern science was for centuries suppressed both in China and in the Islamic world meansthat its rise in Europe should in no way be taken for granted. Europe too had vested interests resistantto technological change and its attendant disruptions. European religious authorities, just as in Islam,were quick to deter challenges to church doctrine. The bishop of Paris, Étienne Tempier, in 1270condemned 13 doctrines held by followers of Aristotle, whose philosophy had gained substantialinfluence in Europe’s universities. The bishop followed up in 1277 by prohibiting 219 philosophicaland theological theses being discussed at the University of Paris.

But Europe differed from China and the Islamic world in that its educational institutes hadconsiderable independence. The European concept of the corporation as a legal person conferred acertain freedom of thought and action on bodies like guilds and universities. Church authorities couldobject to what was being taught or discussed, but they could not permanently suppress scientificideas.

Though Europe’s universities started by teaching theology, like the madrasas, they soon moved on

to the philosophy of Aristotle, and from philosophy to physics and astronomy. Within theseinstitutions, scientists were able to begin the systematic investigation of nature, thus laying the basisfor modern science.

The existence of universities explains how science was able to thrive in Europe though not inChina or the Islamic world, but does not explain how science got started in Europe in the first place.What were the preexisting, nonscientific sources from which the scientific enterprise arose?

Huff presents an interesting idea of where to find them. “The riddle of the success of modernscience in the West—and its failure in non-Western civilizations—is to be solved by studying thenon-scientific domains of culture, that is, religion, philosophy, theology, and the like,” he writes.21

Christian theology had a rich history of argumentation about fine matters of doctrine, many of themstemming from the complex dogma of the Trinity. These disputes shaped in Europeans’ minds the ideaof reason as a human attribute. It was reason that separated man from animal. Helped by therediscovery of Roman civil law toward the end of the 11th century, Europe developed the concept ofa legal system. Reason and conscience were adopted as the criteria for deciding legal practice. So itwas from there a stone’s throw to the concept of laws of nature, to assuming that there existed a Bookof Nature and a World Machine that could be comprehended by human reason. It was the revolutionin legal thought of the 12th and 13th centuries, in Huff’s view, that transformed medieval society inEurope and made it receptive ground for the growth of modern science.

The Rewards of Openness

The concepts of law and reason in Europe that were the wellsprings of modern science served also asthe basis for an open society. Trade and exploration, which Chinese emperors were able to suppresswhen it suited them, became central forces in Europe’s expansion.

Between intermittent bouts of warfare, there was vigorous trade between Europe’s variousregions. Trade was one of the forces behind the European exploration of the world. The 1490s sawVasco da Gama’s visit to India and Columbus’s to the Americas. These voyages also marked adistinctly European curiosity about the world. The exploration was allied with a flood of newtechnical inventions, the beginnings of modern science and the emergence of capitalism.

It was Europe that discovered the world, not the other way around. The Chinese admiral ZhengHe mounted several voyages to Southeast Asia and Africa in the early 15th century, but these werenot sustained. Having discovered the rest of the world, Europeans set up trading routes, followed inmany instances by conquest. Europeans brushed aside tribal societies almost at will, dispatchingsettlers to occupy the Americas, Australia and large tracts of Africa.

The roots of European distinctiveness may have been laid as early as the 11th century, if notbefore, yet even by 1500 Europe’s impending rise was far from evident. The Ottoman empire at thattime was still expanding. China was enjoying a period of stability under the Ming dynasty. TheMughal empire was about to rise in India. All three powers were more substantial than any in Europe.

Europe lacked the military advantage of being united but could afford its fragmentation, thoughonly narrowly, because, unlike China, it was not under continual threat of invasion. Lying at thewestern extremity of the Eurasian landmass, Europe was protected on its eastern flank by the bufferstates of Russia and Byzantium. From the 10th century on, after onslaughts of Vikings, Magyars andMuslims had been turned back, Europe was reasonably free from external attack, and England, withthe extra defense of being an island, enjoyed the greatest security of all.

Hence, unlike the Chinese, Europeans were never forced to seek or accept an autocratic regimestrong enough to protect them from outsiders. They had the luxury of preferring independence and offighting just among themselves. These internal wars let them benefit from the spur of militarycompetition, but the geography and politics of Europe blocked the usual endgame leading to a singlepermanent empire. The post-Roman empires that arose in Europe, whether of Charlemagne, theHapsburgs, Napoleon or Hitler, were never complete and tended to be short-lived.

In authoritarian societies, the ruler can coerce taxes, raise armies and wage war. In principle, theauthoritarian states of China and the Islamic world should have enjoyed greater military power thanEurope’s handful of disunited states, each with a sovereign obliged to various degrees toacknowledge local laws and elites. And so for many centuries they did. Europe in the 13th centurywas no match for the western Mongol army that invaded Poland, Hungary and the Holy RomanEmpire with orders to push to the Atlantic coast; only because the Great Khan Ögedei died in 1241,precipitating a succession crisis, did the Mongols voluntarily withdraw from Europe. After theByzantine state collapsed in 1453, removing the buffer that had separated Europe from the Turkishhorde, Ottoman armies were able to penetrate Europe as far as Vienna in 1529 and again in 1683.

But Europe’s growing wealth and inventiveness eventually reversed its position of militaryweakness. Its backwardness in 1500, compared with the Islamic and Chinese empires, was only

apparent. European expeditions were soon to conquer India, North and South America, Australia andmost of Africa. Europe occupies 7% of the earth’s landmass but came to rule 35% of it by 1800 and84% by 1914.

Unlike in Europe, where science, technology and industry were closely intertwined, technology inChina was never harnessed to industry, and industry was never allowed the space for autonomousdevelopment. China’s enthusiasm for invention had long since ossified. The mandarins had a distastefor novelty. They spurned foreign inventions and lacked the curiosity that drove the intellectuallyadventurous Europeans to reach beyond technology to the scientific principles behind it.

There was no free market nor institutionalized property rights in China. “The Chinese state wasalways interfering with private enterprise—taking over lucrative activities, prohibiting others,manipulating prices, exacting bribes, curtailing private enrichment,” writes the economic historianDavid Landes. “Bad government strangled initiative, increased the cost of transactions, divertedtalent from commerce and industry.” 22

In the lapidary words of Adam Smith, “Little else is requisite to carry a state to the highest degreeof opulence from the lowest barbarism, but peace, easy taxes, and a tolerable administration ofjustice: all the rest being brought about by the natural course of things.” 23 But the “little else” issomething of an understatement. Peace, easy taxes and justice are seldom found together in history.Only in Europe was this magic formula achieved, and it became the basis for Europe’s unexpectedascent in the world.

The Adaptive Response to Different Societies

In his book The Wealth and Poverty of Nations, the economic historian David Landes examinesevery possible factor for explaining the rise of the West and the stagnation of China and concludes, inessence, that the answer lies in the nature of the people. Landes attributes the decisive factor toculture, but describes culture in such a way as to imply race.

“If we learn anything from the history of economic development, it is that culture makes all thedifference,” he writes. “Witness the enterprise of expatriate minorities—the Chinese in East andSoutheast Asia, Indians in East Africa, Lebanese in West Africa, Jews and Calvinists throughoutmuch of Europe, and on and on. Yet culture, in the sense of the inner values and attitudes that guide apopulation, frightens scholars. It has a sulfuric odor of race and inheritance, an air of immutability.” 24

Sulfuric odor or not, the culture of each race, whether genetically based or otherwise, is whatLandes suggests has made the difference in economic development. Given the distinctiveness ofEuropean societies and the period for which they have been on their own path of development—atleast 1,000 years—it is highly likely that the social behavior of Europeans has been adaptinggenetically to the challenges of surviving and prospering in a European society. The data gathered byClark on declining rates of violence and increasing rates of literacy from 1200 to 1800, described inchapter 7, are evidence that this is indeed the case.

Though equivalent data does not exist for the Chinese population, their society has beendistinctive for even longer—at least 2,000 years—and the intense pressures on survival discussed inchapter 7 would have adapted the Chinese to their society just as Europeans became adapted totheirs.

Psychologists who study the behaviors characteristic of European and East Asian populationsusually ascribe everything solely to culture. From an evolutionary perspective, this is implausible. Asociety’s social behavior is central to its survival. Social behavior would have been as closelytailored to prevailing conditions as are the observable features of difference among races such as skinor hair color.

The institutions that characterize a society are a mix of culturally determined and geneticallyinfluenced behaviors. The cultural component can be recognized because it has a generally higher rateof change, despite the conservatism of many cultural institutions. Warfare, for instance, is aninstitution of all human societies, but whether this genetically shaped propensity is exercised dependson culture and circumstances. Germany and Japan developed highly militaristic societies before andduring the Second World War but both are now determinedly pacific. This is a cultural change, onefar too quick to be genetic. There can be little doubt that both nations retain the propensity for warfareand would exercise it if they needed to do so.

A distinctive feature of genetically shaped behaviors is that they persist unchanged over manygenerations. The presence of a genetic anchor would explain why expatriate English populationsthroughout the world have behaved like one another and like their source population over manycenturies, and why the same is true of the Chinese abroad. A genetic basis for these groups’ socialbehavior also explains why it is so hard for other populations to copy their desirable features. TheMalay, Thai or Indonesian populations who have prosperous Chinese populations in their midst mightenvy the Chinese success but are strangely unable to copy it. People are highly imitative, and if

Chinese business success were purely cultural, everyone would find it easy to adopt the samemethods. This is not the case because social behavior, of Chinese and others, is genetically shaped.

The genetic basis of human social behavior is still largely opaque, and it’s hard to tell exactlyhow the neural rules that influence behavior are written. There is clearly a genetic propensity toavoid incest, for example. But it’s very unlikely that the genetic rule is written in exactly those terms.Marriage records from Israeli kibbutzim and Chinese families in Taiwan suggest that in practice theincest taboo is driven by an aversion to marrying partners whom one knew intimately in childhood.So the neural rule is probably something like “If you grew up under the same roof with this person,they are not a suitable marriage partner.”

Do Europeans carry genes that favor open societies and the rule of law? Is there a gene forrespecting property rights or restraining the absolutism of rulers? Obviously this is unlikely to be thecase. No one can yet say exactly what patterns in the neural circuitry predispose Europeanpopulations to prefer open societies and the rule of law to autocracies, or Chinese to be drawn to asystem of family obligations, political hierarchy and conformity. But there is no reason to doubt thatevolution is capable of framing subtle solutions to complex problems of social adaptation.

There is almost certainly a genetic propensity for following society’s rules and punishing thosewho violate them, as noted in chapter 3. If Europeans were slightly less inclined to punish violatorsand Chinese more so, that could explain why European societies are more tolerant of dissenters andinnovators, and Chinese societies less so. Because the genes that govern rule following andpunishment of violators have not yet been identified, it is not yet known if these do in fact vary inEuropean and Chinese populations in the way suggested. Nature has many dials to twist in setting theintensities of the various human social behaviors and many different ways of arriving at the samesolution.

The rise of the West was not some cultural accident. It was the direct result of the evolution ofEuropean populations as they adapted to the geographic and military conditions of their particularecological habitat. That European societies have turned out to be more innovative and productive thanothers, at least under present circumstances, does not of course mean that Europeans are superior toothers—a meaningless term in any case from the evolutionary perspective. Europeans are much likeeveryone else except for minor differences in their social behavior. But these minor differences, forthe most part invisible in an individual, have major consequences at the level of a society. Europeaninstitutions, a blend of both culture and European adaptive social behavior, are the reason thatEuropeans have constructed innovative, open and productive societies. The rise of the West is anevent not just in history but also in human evolution.

I

10

EVOLUTIONARY PERSPECTIVESON RACE

magine that you, if an English speaker of European descent, are standing on a hill with someonefrom East Asia and another from Africa. Through a slip in the space-time continuum, yousuddenly find that you are holding your mother’s hand, and she your grandmother’s, and so onthrough a long line of ancestors that stretches down the hill. The same living ancestors have

appeared beside the East Asian and the African, and the three lines of women holding hands snakedown the hillside to the valley below.

You let go of your mother’s hand and walk down the hill to review the three lineages. The womenholding one another’s hands are standing 3 feet apart. The average generation time through most ofhistory has been around 25 years, meaning there have been four generations per century. So every 12feet you walk encompasses a century of ancestresses, and every 120 feet a thousand years.

You pass by your ancestors in wonder but cannot communicate with them; the shifting languagesthey speak are now far ancestral to English. Their faces soon lose their distinctively Europeanfeatures, although their skin is still pale. After you have walked 3,600 feet, just over two thirds of amile, a strange thing happens. A woman is standing between your line of ancestresses and those of theEast Asian and at her position the two lines merge into one. She is holding in one hand the hands ofher two daughters, one of whom is first in the European line and the other the first in the East Asianline.

As you continue down the hill, you are reviewing just two lineages, the now joint European–EastAsian line and that of Africans. The people in the joint line grow steadily darker in complexion, sincethey lived before humans expanded to extreme northern latitudes and developed pale skin. Then, afteryou’ve been walking just over a mile, it is the turn of these two lineages to converge into one. Therestands a woman holding the hands of two daughters, one of whom stayed in Africa and the otherjoined the small hunter-gatherer band that left the ancestral homeland some 50,000 years ago. In awalk of some 22 minutes, the human species has been reunified before your eyes.

Had you continued walking for another hour, all of it along African ancestors, you would havereached the 200,000 year mark, the earliest known appearance of modern humans. Three quarters ofmodern human existence has been spent in Africa, only the last quarter outside it. Today’s races holdthree quarters of their history in common, only one quarter apart.1

From an evolutionary perspective, the human races are all very similar variations of the samegene pool. The question that looms over all the social sciences, unanswered and largely unaddressed,is how to explain the paradox that people as individuals are so similar yet human societies differ soconspicuously in their cultural and economic attainments.

The argument presented in the pages above is that these differences do not spring from any greatdisparity between the individual members of the various races. Rather, they stem from the quite minorvariations in human social behavior, whether of trust, conformity, aggressiveness or other traits, thathave evolved within each race during its geographical and historical experience. These variationshave set the framework for social institutions of significantly different character. It is because of theirinstitutions—which are largely cultural edifices resting on a base of genetically shaped socialbehaviors—that the societies of the West and of East Asia are so different, that tribal societies are sounlike modern states, and that rich countries are rich and poor countries deprived.

The consensus explanation of almost all social scientists is that human societies differ only intheir culture, with the implicit premise that evolution has played no role in the differences betweenpopulations. But the all-culture explanation is implausible for several reasons.

First, it is of course a conjecture. No one can at present say what precise mix of genetics andculture underlies the differences between human societies, and the assertion that evolution plays norole is merely a surmise.

Second, the all-culture position was formulated largely by the anthropologist Franz Boas as anantiracist position, which may be laudable in motive, but political ideology of any kind has no properplace in science. Moreover Boas wrote at a time before it was known that human evolution had nothalted in the distant past.

Third, the all-culture conjecture does not satisfactorily explain why the differences betweenhuman societies are as deep-rooted as seems to be the case. If the differences between a tribal societyand a modern state were purely cultural, it should be easy to modernize a tribal society by importingWestern institutions. American experience in Haiti, Iraq and Afghanistan generally suggestsotherwise. Culture undeniably explains many important differences between societies. The issue iswhether it is a sufficient explanation for all such differences.

Fourth, the all-culture conjecture is severely lacking in proper care and maintenance. Its adherentshave failed to update it to take account of the new discovery that human evolution has been recent,copious and regional. Their hypothesis must assume, against all the evidence that has accumulatedover the past 30 years, that the mind is a blank slate, born immaculately bereft of any innate behavior,and that the importance of social behavior for survival is too trivial to have been molded by naturalselection. Or, if they allow that social behavior does have a genetic basis, they must explain how itcould have remained unchanged in all races, despite the vast changes in human social structure overthe past 15,000 years, when many other traits are now known to have evolved independently in eachrace, transforming some 14% of the human genome.

The thesis presented here assumes, to the contrary, that there is a genetic component to humansocial behavior; that this component, so critical to human survival, is subject to evolutionary changeand has indeed evolved over time; that the evolution in social behavior has necessarily proceededindependently in the five major races and others; and that slight evolutionary differences in socialbehavior underlie the differences in social institutions prevalent among the major human populations.

Like the all-culture position, this thesis is unproven, but it rests on several premises that areplausible in the light of new knowledge.

The first is that the social structures of primates, humans included, are based on geneticallyshaped behaviors. Chimpanzees inherited a genetic template for operation of their distinctivesocieties from their joint ancestor with humans. The joint ancestor would have bequeathed the same

template to the human lineage, which then evolved to support the distinctive features of human socialstructure, from the pair bonding that emerged some 1.7 million years ago to the emergence of hunter-gatherer bands and tribes. It is hard to see why humans, as an intensely social species, should everhave lost the genetic template for the suite of social behaviors on which their society depends, or whythe template should not have continued to evolve during the most dramatic of all its transformations,the shift that enabled the size of human societies to expand from a maximum of 150 in the hunter-gatherer group to vast cities teeming with tens of millions of inhabitants. This transformation, itshould be noted, had to evolve independently in the major races since it occurred after they splitapart.

A variety of data, including experiments with very young children, points to innate socialpropensities for cooperativeness, helping others, obeying rules, punishing those who don’t, trustingothers selectively and a sense of fairness. The genes that direct the neural circuitry for such behaviorsare for the most part unknown. But it is plausible that they exist, and genetic systems involving thecontrol of the enzyme MAO-A, associated with aggression, and the hormone oxytocin, a modulator oftrust, are already known.

A second premise is that these genetically shaped social behaviors undergird the institutionsaround which human societies are constructed. Given that such behaviors exist, it seemsuncontroversial that institutions should depend on them, and the proposition is endorsed by authoritiessuch as the economist Douglass North and the political scientist Francis Fukuyama, both of whom seeinstitutions as founded in the genetics of human behavior.

A third premise is that the evolution of social behavior has continued during the past 50,000 yearsand throughout the historical period. This phase of evolution has necessarily occurred independentlyand in parallel in the three major races after they split apart and each made the transition from huntingand gathering to settled life. Evidence in the genome that human evolution has been recent, copiousand regional provides general support for this thesis, unless any reason can be shown why socialbehavior should have been exempt from natural selection.

The best possible proof of the premise would be identification of the genes that shape the neuralcircuitry for social behaviors, and demonstration that they have been under natural selection in eachrace. No such test is yet available because the genes that underlie social behavior are largelyunknown. But brain genes of unknown duties are among the genes found to have been under recentselective pressure in the three principal races, proving that the genes for neural function are notexempt from recent evolutionary change. In addition, the MAO-A gene, which influences aggressivity,varies substantially among races and ethnicities in a way that suggests, though does not prove, that thegene has been under evolutionary pressure.

A fourth premise is that evolved social behavior can in fact be observed in today’s variouspopulations. The behavioral changes documented in the English population during the 600 years thatpreceded the Industrial Revolution include a decline in violence and increases in literacy, thepropensity to work and the propensity to save. The same evolutionary shift presumably occurred inthe other agrarian populations of Europe and East Asia before they entered their own industrialrevolutions. Another behavioral change is evident in the Jewish population as it adapted over thecenturies first to educational demands and then to exacting professional niches.

A fifth premise is that the significant differences are those between human societies, not theirindividual members. Human nature is essentially the same worldwide. But minor variations in social

behavior, though barely perceptible, if at all, in an individual, combine to create societies of verydifferent character. These evolutionary differences between societies on the various continents mayunderlie major and otherwise imperfectly explained turning points in history such as the rise of theWest and the decline of the Islamic world and China, as well as the economic disparities that beganto emerge in the past few centuries.

To assert that evolution has played some role in human history does not mean that that role isnecessarily prominent, let alone decisive. Culture is a mighty force, and people are not slaves toinnate propensities, which in any case only prompt the mind in a certain direction. But if allindividuals in a society have similar propensities, however slight, toward greater or less social trust,say, or greater or lesser conformity, then the society will tend to act in that direction and to differfrom societies that lack such propensities.

History as If Evolution Mattered

How might historians write if they believed that evolution were relevant to their concerns? Theywould surely pay greater attention to the evolutionary role of forces like demography and warfare inshaping human societies. Population growth seems to have been the driving force that compelledsocieties to devise more complex structures, both in order to organize larger numbers of people andfor defense against neighbors who were also expanding in numbers and territory. Under the pressureof war, chiefdoms coalesced into archaic states and states into empires. But this sanguinary processfaltered if populations were too sparse or people could escape elsewhere.

The forces of natural selection that work within a society have been equally significant. Agrarianeconomies have kept people striving at the edge of starvation for millennia, the condition in whichDarwin perceived that natural selection would favor even the slightest survival advantage. Underthese Malthusian conditions, the ratchet of wealth—the ability of the rich to raise more survivingchildren—slowly diffused the social behaviors required for modern prosperity into the wider society.

These forces have worked independently on the populations in each continent, driving them alongpaths that were parallel to a large extent but ultimately diverged. Early states arose in East Asia,Europe, Africa and the two Americas. In Australia, however, population numbers and climateremained too adverse to induce the development of agriculture or social structures more elaboratethan that of hunter-gatherers.

Human societies of distinctive character arose on all five continents and some became the basisfor major civilizations. Historians reject thinking in racial categories for understandable reasons. Butit is an error to exclude any possible role for evolution in history. The major civilizations occurwithin the two main races of East Asians and Caucasians, as distinguished by genetics. Within theEast Asian race arose the civilizations of China, Korea and Japan, as well as Siberian steppe culturessuch as the Mongols. Within the Caucasian group are the civilizations of India, Russia, the West,South America and the Islamic world.

A primary effect of genetics is to add a substantial degree of inertia or stability to the socialbehavior and hence to the institutions of each society. Rapid change must be due to culture, notgenetics, but if the core social behaviors of each civilization have an evolutionary foundation, asargued in the previous chapter, then the rate of change in their relationships is likely to beconstrained. The slow march of evolution, in other words, exerts an unseen collar on the pace ofhistory.

This constraint has considerable bearing on issues such as whether the West will continue itsdominance or enter into decline. “What we are living through now is the end of 500 years of Westernpredominance. This time the Eastern challenger is for real,” the historian Niall Ferguson wrote in2011.2 Ferguson’s basic argument is that empires have always risen and fallen, therefore the UnitedStates too will be eclipsed, and the most likely successor on the horizon is China. But the rise and fallof civilizations is in fact vastly slower than that of empires. In Europe, the empires of Charlemagne,the Hapsburgs, Napoleon and Hitler all rose and fell, without having any significant effect on the riseof Western civilization. Dynasties have changed in China, some of them led by invaders like theMongols or Manchus, without altering the essential character of Chinese social behavior. Empires arean epiphenomenon upon the surface of the stronger, slower tides of evolution.

Of greater moment are the clashes between the world’s civilizations. War was the mechanism thatwelded early human societies into the first primitive states and has been a constant shaper of stateorganization ever since. There is no clear reason why continued militarism should not haveculminated in a single worldwide empire as soon as transport and communications permitted. TheMongol imperium, a rapacious and highly destructive society that stretched from Eastern Europe tothe Sea of Japan, was a prototype of such a universal empire. The Mongol sack of Baghdad destroyedthe leading center of Islamic culture. The capitals of Europe nearly suffered the same fate: if theMongol army that conquered Poland and Hungary had continued its march to the Atlantic coast, aswas its plan, the rise of the West would have been aborted or at the least substantially delayed.

Western civilization was certainly expansionary, but after a comparatively brief colonial phase ithas refocused on the trade and productive investment that drove its expansion in the first place. Itseems a fortunate outcome that the world’s dominant military power has turned out to be the West,with a system of international trade and law that offers benefits to all participants, and not a purelypredatory and militaristic state like that of the Mongols or Ottomans, as might have been expected, oreven a civilized but autocratic one like that of China.

From an evolutionary perspective, an imminent decline of the West seems unlikely. Westernsocial behavior, the source of the open society and open economy with their rewards to innovation,has been shaped by evolution as well as by culture and history and is unlikely to change anytime soon.The West was more exploratory and innovative than other civilizations in 1500 and it is the same waynow. Neither Japan nor China has yet seriously challenged the West’s preeminence in science andtechnology despite ample investments and a large body of educated and capable scientists. Well-performing institutions don’t guarantee the West’s permanent dominance but the social behavior thatunderlies them is an asset that is likely to persist for many generations, barring some major setback.East Asian societies seem too authoritarian and conformist, despite the high abilities of their citizens,to challenge the innovation of the West, a fact implicitly acknowledged in the Chinese state’s intenseefforts to steal Western technical and commercial secrets.

But the success of the West, even if long lasting, is necessarily provisional. The framework ofsocial behavior at the root of the West’s critical institutions may be frailer than it seems andvulnerable to being overwhelmed by adverse cultural forces such as political stasis, class warfare ora failure of social cohesion. Western societies are well adapted to present economic conditions,which they have in large measure created. In different conditions, the West’s advantage mightdisappear. If the present climatic regime should change substantially, for instance in the globalcooling that will precede the inevitable onset of the next ice age, more authoritarian societies likethose of East Asia could be better positioned to endure harsh stresses. By evolution’s criterion ofsuccess, East Asians are already the most successful human population: the Han Chinese are theworld’s most numerous ethnic group. By another biological criterion, the population of Africa is themost important, since it harbors the most genetic diversity and hence a larger share of the humangenetic patrimony than any other race.

The various races and ethnicities into which humans have evolved represent a grand experimentin which nature has tested out some of the variations inherent in the human genome. The experiment isnot being conducted in our interests—it has no purpose or goal—yet it offers considerable benefits.Instead of there being a single type of human society, there are many, creating a rich diversity ofcultures whose more promising features can be adopted and improved on by others. Without Western

production efficiencies, the countries of East Asia might still be locked in stagnant autocracies.Within the West, the success of Jews has benefited every economy in which they worked andcontributed immeasurably to the arts and sciences. The strong cultures of East Asia may yet find waysto surpass the West, as they have done for most of their previous history.

Understanding Race

The idea that human populations are genetically different from one another has been actively ignoredby academics and policy makers for fear that such inquiry might promote racism. The argumentoffered here is that people the world over are highly similar as individuals but that societies differwidely because of evolutionary differences in social behavior. It would be better to take account ofevolutionary differences than to continue to ignore them.

Moreover, fears that the evolutionary understanding of race will promote a new phase of racismor imperialism are surely exaggerated. The lessons of past abuses are still vivid enough. Science maybe an autonomous body of knowledge, but its interpretation depends strongly on the intellectualclimate of the time. In the 19th century, a period of vigorous European expansion, people looked toSocial Darwinism to justify dominion over others and deny welfare to the poor. This interpretation ofDarwinism has been so thoroughly repudiated that it is hard to conceive of any circumstance in whichit could be successfully resurrected.

But is it not a form of racism to link the success of the West to the genetics of Westerners? Forseveral reasons, this is not the case. First, there is no assertion of superiority, which is the essence ofracism, and in any case the success of the West is provisional. Its economies are an open book, freefor all others to copy, as they are doing, and to improve on. As everyone understands, China is arising power whose role in the world has yet to be defined. Nations are compared on metrics such aseconomic or military power, which are constantly shifting and allow none the right or reason to claimpermanent dominance, let alone inherent superiority.

Second, a society’s achievements, whether in economics or the arts or military preparedness,rests in the first place on its institutions, which are largely cultural in essence. Genes may nudgesocial behavior in one direction or another, thus affecting the nature of a society’s institutions on thetimescale of the generations and setting the framework within which culture operates, but this is along-term effect that leaves ample room for culture to play a major role.

Third, all human races are variations on a common theme. There is no basis from an evolutionaryperspective, or any other, for declaring any one variation superior to any other.

One reason why discussion of genetics is so fraught is because of the assumption that genes areimmutable and that to say a person or group of people carries a disadvantageous gene puts thembeyond remedy. This is at best a partial truth.

The genes whose effects cannot be changed, like those that direct the color of skin or hair or theproportions of the body, are or should be of no relevance to the success of a modern economy. Theimportant genes, at least in terms of the differences between civilizations, are those that influencesocial behavior.

But the genes that govern human behavior seldom issue imperatives. They operate by setting mereinclinations, of which even the strongest can be overridden. There are almost certainly genes thatpredispose people to regard incest as abhorrent, yet cases of incest are far from rare because thoseneural prohibitions can be ignored. Because the prompting of behavioral genes can be resisted,ingrained social behavior may be subject to a variety of manipulations, ranging from education andsocial pressure to tax incentives. In short, many social behaviors are modifiable and this is probablythe case even if they are genetically influenced. Where behavior is concerned, genetic does not mean

immutable.Many forms of new knowledge are potentially dangerous, the energy of the atom being a

preeminent example. But instead of curtailing inquiry Western societies have in general assumed thatthe better policy is to continue exploration in confidence that the rewards can be reaped and the risksmanaged. It is hard to see why exploration of the human genome and its racial variations should bemade an exception to this principle, even though researchers and their audience must first develop thewords and concepts to discuss a dangerous subject objectively.

Knowledge is usually considered a better basis for policy than ignorance. This book has been anattempt, undoubtedly imperfect, to dispel the fear of racism that overhangs discussion of human groupdifferences and to begin to explore the far-reaching implications of the discovery that humanevolution has been recent, copious and regional.

ACKNOWLEDGMENTS

This book, like its predecessor The Faith Instinct, grew out of Before the Dawn, an account ofhuman evolution in the past 50,000 years.

The Faith Instinct examined the evolutionary role of religion as a cohesive force in humansocieties. This book explores new data from the human genome that has shed light on the emergenceof the various races of humankind. Both religion and race are essential but strangely unexploredaspects of the human experience. Like everything else in biology, they make no sense except in thelight of evolution.

I thank Peter Matson of Sterling Lord Literistic for guiding the initial focus of the book. I am mostgrateful to Scott Moyers of Penguin Press for thoroughly critiquing the book and guiding it past manyperilous shoals with unswerving editorial skill.

I owe a great debt to friends who read early drafts and saved me from many errors of fact andjudgment, including Nicholas W. Fisher of the University of Aberdeen, Jeremy J. Stone of CatalyticDiplomacy, Richard L. Tapper of the London School of Oriental and African Studies and my sonAlexander Wade of Doctors Without Borders.

NOTES

CHAPTER 1: EVOLUTION, RACE AND HISTORY

1. Joshua M. Akey, “Constructing Genomic Maps of Positive Selection in Humans: Where Do We Go from Here?” Genome Research19 (2009): 711–22.

2. Xin Yi et al., “Sequencing of 50 Human Exomes Reveals Adaptation to High Altitude,” Science 329, no. 5987 (July 2, 2010): 75–78.3. Emmanuel Milot et al., “Evidence for Evolution in Response to Natural Selection in a Contemporary Human Population,” Proceedings

of the National Academy of Sciences 108 (2011): 17040–45.4. Stephen C. Stearns et al., “Measuring Selection in Contemporary Human Populations,” Nature Reviews Genetics 11, no. 9 (Sept.

2010): 1–13.5. American Anthropological Association, “Race: A Public Education Project,” www.aaanet.org/resources/A-Public-Education-

Program.cfm.6. Alan H. Goodman, Yolanda T. Moses, and Joseph L. Jones, Race: Are We So Different? (Arlington, VA: American Anthropological

Association 2012), 2.7. American Sociological Association, “The Importance of Collecting Data and Doing Social Scientific Research on Race,” (Washington,

DC: American Sociological Association, 2003), www2.asanet.org/media/asa_race_statement.pdf.8. Christopher F. Chabris et al., “Most Reported Genetic Associations with General Intelligence Are Probably False Positives,”

Psychological Science 20, no. 10 (Sept. 24, 2012): 1–10.9. David Epstein, The Sports Gene: Inside the Science of Extraordinary Athletic Performance (New York: Current, 2013), 176.

CHAPTER 2: PERVERSIONS OF SCIENCE

1. Richard Hofstadter, Social Darwinism in American Thought (Boston: Beacon Press, 1992), 171.2. Benjamin Isaac, The Invention of Racism in Classical Antiquity (Princeton, NJ: Princeton University Press, 2004), 23.3. Nell Irving Painter, “Why White People Are Called ‘Caucasian’?” paper presented at the Fifth Annual Gilder Lehrman Center

International Conference, Yale University, New Haven, CT, Nov. 7–8, 2003, www.yale.edu/glc/events/race/Painter.pdf.4. Jason E. Lewis et al., “The Mismeasure of Science: Stephen Jay Gould Versus Samuel George Morton on Skulls and Bias,” PLoS

Biology 9, no. 6 (June 7, 2011), www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1001071.5. Hofstadter, Social Darwinism, xvi.6. Charles Darwin, The Descent of Man and Selection in Relation to Sex, 2d ed. (New York: Appleton, 1898), 136.7. Nicholas Wright Gillham, A Life of Sir Francis Galton: From African Exploration to the Birth of Eugenics (New York: Oxford

University Press, 2001), 166.8. Ibid., 357.9. Edwin Black, War Against the Weak: Eugenics and America’s Campaign to Create a Master Race (New York: Four Walls Eight

Windows, 2003), 37.10. Ibid., 45–47.11. Ibid., 90.12. Daniel J. Kevles, In the Name of Eugenics: Genetics and the Uses of Human Heredity (New York: Knopf, 1985), 69.13. Black, War Against the Weak, 87.14. Ibid., 99.15. Kevles, In the Name of Eugenics, 81.16. Ibid., 106.17. Black, War Against the Weak, 123.18. Kevles, In the Name of Eugenics, 97.19. Black, War Against the Weak, 393.20. Madison Grant, The Passing of the Great Race; or, The Racial Basis of European History, 4th ed. (New York: Charles Scribner,

1932), 170.21. Ibid., 263.22. Jonathan P. Spiro, Defending the Master Race: Conservation, Eugenics and the Legacy of Madison Grant (Burlington:

University of Vermont Press, 2009), 375.23. Black, War Against the Weak, 100.24. Ibid., 259.25. Kevles, In the Name of Eugenics, 117.

26. Ibid., 118.27. Raul Hilberg, The Destruction of the European Jews (New York: Holmes & Meier, 1985, student edition), 31.28. Yvonne Sherratt, Hitler’s Philosophers (New Haven, CT: Yale University Press, 2013) 60.

CHAPTER 3: ORIGINS OF HUMAN SOCIAL NATURE

1. Bernard Chapais, Primeval Kinship: How Pair-Bonding Gave Birth to Human Society (Cambridge, MA: Harvard UniversityPress, 2008), 4.

2. Charles Darwin, The Descent of Man and Selection in Relation to Sex, 2d ed. (New York: Appleton, 1898), 131.3. Michael Tomasello, Why We Cooperate (Cambridge, MA: MIT Press, 2009), 27.4. Ibid., 23.5. Ibid., 7.6. Esther Herrmann et al., “Humans Have Evolved Specialized Skills of Social Cognition: The Cultural Intelligence Hypothesis,” Science

317, no. 5843 (Sept. 7, 2007): 1360–66.7. Michael Tomasello and Malinda Carpenter, “Shared Intentionality,” Developmental Science 10, no. 1 (2007): 121–25.8. Cade McCall and Tania Singer, “The Animal and Human Neuroendocrinology of Social Cognition, Motivation and Behavior,” Nature

Neuroscience 15 (2012): 681–88.9. Carsten K. W. De Dreu et al., “Oxytocin Promotes Human Ethnocentrism,” Proceedings of the National Academy of Sciences

108, no. 4 (Jan. 25, 2011), 1262–66.10. David H. Skuse et al., “Common Polymorphism in the Oxytocin Receptor Gene (OXTR) Is Associated With Human Recognition

Skills,” Proceedings of the U.S. National Academy of Sciences (December 23, 2013).11. Reviewed in Zoe R. Donaldson and Larry J. Young, “Oxytocin, Vasopressin and the Neurogenesis of Sociality,” Science 322, no.

5903 (Nov. 7, 2008): 900–904.12. Nicholas Wade, “Nice Rats, Nasty Rats: Maybe It’s All in the Genes,” New York Times, July 25, 2006,

www.nytimes.com/2006/07/25/health/25rats.html?pagewanted=all&_r=0 (accessed Sept. 25, 2013).13. Robert R. H. Anholt and Trudy F. C. Mackay, “Genetics of Aggression,” Annual Reviews of Genetics 46 (2012): 145–64.14. Guang Guo et al., “The VNTR 2 Repeat in MAOA and Delinquent Behavior in Adolescence and Young Adulthood: Associations

and MAOA Promoter Activity,” European Journal of Human Genetics 16 (2008): 624–34.15. Yoav Gilad et al., “Evidence for Positive Selection and Population Structure at the Human MAO-A Gene,” Proceedings of the

National Academy of Sciences 99, no. 2 (Jan. 22, 2002): 862–67.16. Kevin M. Beaver et al., “Exploring the Association Between the 2-Repeat Allele of the MAOA Gene Promoter Polymorphism and

Psychopathic Personality Traits, Arrests, Incarceration, and Lifetime Antisocial Behavior,” Personality and IndividualDifferences 54, no. 2 (Jan. 2013): 164–68.

17. Laura Bevilacqua et al., “A Population-Specific HTR2B Stop Codon Predisposes to Severe Impulsivity,” Nature 468, no. 7327 (Dec.23, 2010): 1061–66.

18. Edward O. Wilson, Sociobiology: The New Synthesis (Cambridge, MA: Harvard University Press, 1975), 547–75.19. Edward O. Wilson, On Human Nature (Cambridge, MA: Harvard University Press, 1978), 167.20. Sarah A. Tishkoff et al., “Convergent Adaptation of Human Lactase Persistence in Africa and Europe,” Nature Genetics 39, no. 1

(Jan. 2007): 31–40.21. Hillard S. Kaplan, Paul L. Hooper, and Michael Gurven, “The Evolutionary and Sociological Roots of Human Social Organization,”

Philosophical Transactions of the Royal Society B: Biological Science 364, no. 1533 (Nov. 12, 2009): 3289–99.

CHAPTER 4: THE HUMAN EXPERIMENT

1. Charles Darwin, The Descent of Man and Selection in Relation to Sex, 2d ed. (New York: Appleton, 1898), 171.2. Ian Tattersall and Rob DeSalle, Race? Debunking a Scientific Myth (College Station: Texas A&M University Press, 2011).3. J. Craig Venter, A Life Decoded: My Genome, My Life (New York: Penguin Books, 2008).4. Jared Diamond, “Race Without Color,” Discover, Nov. 1994.5. Francis S. Collins and Monique K. Mansoura, “The Human Genome Project: Revealing the Shared Inheritance of All Humankind,”

Cancer supplement, Jan. 2001.6. Jerry A. Coyne, “Are There Human Races?” Why Evolution Is True, http://whyevolutionistrue.wordpress.com/2012/02/28/are-there-

human-races.7. Ashley Montagu, Man’s Most Dangerous Myth: The Fallacy of Race, 6th ed. (Lanham, MD: AltaMira Press/Rowman &

Littlefield, 1997), 41.8. Ibid., 47.9. Norman J. Sauer, “Forensic Anthropology and the Concept of Race: If Races Don’t Exist, Why Are Forensic Anthropologists So

Good at Identifying Them?” Social Science and Medicine 34, no. 2 (Jan. 1992): 107–11.10. Winthrop D. Jordan, The White Man’s Burden: Historical Origins of Racism in the United States (New York: Oxford University

Press, 1974), xi–xii.11. John Novembre et al., “Genes Mirror Geography Within Europe,” Nature 456, no. 7218 (Nov. 6, 2008): 98–101.12. Colm O’Dushlaine et al., “Genes Predict Village of Origin in Rural Europe,” European Journal of Human Genetics 18, no. 11

(Nov. 2010): 1269–70.13. See, for example, The History and Geography of Human Genes (Princeton, NJ: Princeton University Press, 1994), a classic work

by L. Luca Cavalli-Sforza, Paolo Menozzi, and Alberto Piazza.14. Esteban J. Parra, “Human Pigmentation Variation: Evolution, Genetic Basis, and Implications for Public Health,” Yearbook of

Physical Anthropology 50 (2007): 85–105.15. Rebecca L. Lamason et al., “SLC24A5, a Putative Cation Exchanger, Affects Pigmentation in Zebrafish and Humans,” Science 310,

no. 5755 (Dec. 16, 2005): 1782–86.16. Akihiro Fujimoto et al., “A Scan for Genetic Determinants of Human Hair Morphology: EDAR Is Associated with Asian Hair

Thickness,” Human Molecular Genetics 17, no. 6 (Mar. 15, 2008): 835–43.17. Yana G. Kamberov et al., “Modeling Recent Human Evolution in Mice by Expression of a Selected EDAR Variant,” Cell 152, no. 4

(Feb. 14, 2013): 691–702.18. Koh-ichiro Yoshiura et al., “A SNP in the ABCC11 Gene Is the Determinant of Human Earwax Type,” Nature Genetics 38, no. 3

(Mar. 2006): 324–30.

CHAPTER 5: THE GENETICS OF RACE

1. Charles Darwin, The Descent of Man and Selection in Relation to Sex, 2d ed. (New York: Appleton, 1898), 132.2. A. M. Bowcock et al., “High Resolution of Human Evolutionary Trees with Polymorphic Microsatellites,” Nature 368, no. 6470 (Mar.

31, 1994): 455–57.3. Neil Risch, Esteban Burchard, Elad Ziv, and Hua Tang, “Categorization of Humans in Biomedical Research: Genes, Race and

Disease,” Genome Biology 3, no. 7 (March 2002), http://genomebiology.com/2002/3/7/comment/2007.4. Noah A. Rosenberg et al., “Genetic Structure of Human Populations,” Science 298, no. 5602 (Dec. 20, 2002): 2381–85.5. Frank B. Livingstone and Theodosius Dobzhansky, “On the Non-Existence of Human Races,” Current Anthropology 3 no. 3 (June

1962): 279.6. David Serre and Svante Pääbo, “Evidence for Gradients of Human Genetic Diversity Within and Among Continents,” Genome

Research 14 (2004): 1679–85.7. Noah A. Rosenberg et al., “Clines, Clusters, and the Effect of Study Design on the Inference of Human Population Structure,” PLoS

Genetics 1, no. 6 (2005): 660–71.8. Jun Z. Li et al., “Worldwide Human Relationships Inferred from Genome-Wide Patterns of Variation,” Science 319, no. 5866 (Feb.

22, 2008): 1100–1104.9. Sarah A. Tishkoff et al., “The Genetic Structure and History of Africans and African Americans,” Science 324, no. 5930 (May 22,

2009): 1035–44.10. Benjamin F. Voight, Sridhar Kudaravalli, Xiaoquan Wen, Jonathan K. Pritchard, “A Map of Recent Positive Selection in the Human

Genome,” PLoS Biology 4, no. 3 (Mar. 2006): 446–53.11. Sharon R. Grossman et al., “Identifying Recent Adaptations in Large-Scale Genomic Data,” Cell 152, no. 4 (Feb. 14, 2013): 703–13.12. Ibid. These figures are not provided in the text but can be gleaned from a supplementary spreadsheet, Table S2.13. Joshua M. Akey, “Constructing Genomic Maps of Positive Selection in Humans: Where Do We Go from Here?” Genome Research

19, no. 5 (May 2009): 711–22.14. Ralf Kittler, Manfred Kayser, and Mark Stoneking, “Molecular Evolution of Pediculus humanus and the Origin of Clothing,”

Current Biology 13, no. 16 (Aug. 19, 2003): 1414–17. Another louse researcher, David Reed, has argued that a much older date,perhaps 500,000 years ago, is correct.

15. David López Herráez et al., “Genetic Variation and Recent Positive Selection in Worldwide Human Populations: Evidence fromNearly 1 Million SNPs,” PLoS One 4, no. 11 (Nov. 18, 2009): 1–16.

16. Graham Coop et al., “The Role of Geography in Human Adaptation,” PLoS Genetics 5, no. 6 (June 2009): 1–16.17. Matthew B. Gross and Cassandra Kniffen, “Duffy Antigen Receptor for Chemokines: DARC,” Online Mendelian Inheritance in

Man, Dec. 10, 2012, http://omim.org/entry/613665.18. C. T. Miller et al., “cis-Regulatory Changes in Kit Ligand Expression and Parallel Evolution of Pigmentation in Sticklebacks and

Humans,” Cell 131 (2007): 1179–89.19. Ryan D. Hernandez et al., “Classic Selective Sweeps Were Rare in Recent Human Evolution,” Science 331, no. 6019 (Feb. 18,

2011): 920–24.20. Jonathan K. Pritchard, “Adaptation—Not by Sweeps Alone,” Nature Reviews Genetics 11, no. 10 (Oct. 2010): 665–67.21. Hua Tang et al., “Genetic Structure, Self-Identified Race/Ethnicity, and Confounding in Case-Control Association Studies,” American

Journal of Human Genetics 76, no. 2 (Feb. 2005): 268–75.22. Roman Kosoy et al., “Ancestry Informative Marker Sets for Determining Continental Origin and Admixture Proportions in Common

Populations in America,” Human Mutation 30, no. 1 (Jan. 2009): 69–78.

23. Wenfei Jin et al., “A Genome-Wide Detection of Natural Selection in African Americans Pre- and Post-Admixture,” GenomeResearch 22, no. 3 (Mar. 1, 2012): 519–27.

24. Richard Lewontin, “The Apportionment of Human Diversity,” Evolutionary Biology 6 (1972): 396–97, quoted in Ashley Montagu,Man’s Most Dangerous Myth: The Fallacy of Race, 6th ed. (Lanham, MD: AltaMira Press/Rowman & Littlefield, 1997), 45–46.

25. Quoted in Daniel L. Hartl and Andrew G. Clark, Principles of Population Genetics, 3d ed. (Sunderland, MA: Sinauer Associates,1997), 119.

26. Quoted by Henry Harpending and Alan R. Rogers, “Genetic Perspectives in Human Origins and Differentiation,” Annual Review ofGenomics and Human Genetics 1 (2000): 361–85.

27. A.W.F. Edwards, “Human Genetic Diversity: Lewontin’s Fallacy,” BioEssays 25, no. 8 (Aug. 2003): 798–801.28. Ed Hagen, “Biological Aspects of Race,” American Association of Physical Anthropologists position statement, American Journal

of Physical Anthropology 101 (1996): 569–70, www.physanth.org/association/position-statements/biological-aspects-of-race.29. American Anthropological Association, “Statement on ‘Race,’” May 17, 1998, www.aaanet.org/stmts/racepp.htm.

CHAPTER 6: SOCIETIES AND INSTITUTIONS

1. Norbert Elias, The Germans: Power Struggles and the Development of Habitus in the Nineteenth and Twentieth Centuries(New York: Columbia University Press, 1996), 18–19.

2. Douglass C. North, Understanding the Process of Economic Change (Princeton, NJ: Princeton University Press, 2005), 99.3. Nicholas Wade, The Faith Instinct: How Religion Evolved and Why It Endures (New York: Penguin Press, 2010), 124–43.4. Napoleon A. Chagnon, “Life Histories, Blood Revenge, and Warfare in a Tribal Population,” Science 239, no. 4843 (Feb. 28, 1988):

985–92.5. Robert L. Carneiro, “A Theory of the Origin of the State,” Science 169, no. 3947 (Aug. 21, 1970): 733–38.6. Francis Fukuyama, The Origins of Political Order: From Prehuman Times to the French Revolution (New York: Farrar, Straus &

Giroux, 2011), vol. 1, p. 48.7. Ibid., 99.8. “The Book of Lord Shang,” Wikipedia, http://en.wikipedia.org/wiki/The_Book_of_Lord_Shang.9. Fukuyama, Origins of Political Order, 421.10. Ibid., 14.11. Daron Acemog˘lu and James A. Robinson, Why Nations Fail: The Origins of Power, Prosperity, and Poverty (New York:

Crown, 2012), 398.12. Ibid., 364.

CHAPTER 7: THE RECASTING OF HUMAN NATURE

1. Thomas Sowell, Conquests and Cultures: An International History (New York: Basic Books, 1999), 329.2. Kenneth Pomeranz, The Great Divergence: China, Europe, and the Making of the Modern World Economy (Princeton, NJ:

Princeton University Press, 2000), 3.3. Gregory Clark, A Farewell to Alms: A Brief Economic History of the World (Princeton, NJ: Princeton University Press 2007), 127.4. Ibid., 179.5. Ibid., 234.6. Nicholas Wade, Before the Dawn: Recovering the Lost History of Our Ancestors (New York: Penguin Press, 2007), 112.7. Clark, Farewell to Alms, 259.8. Ibid., 245.9. Gregory Clark, “The Indicted and the Wealthy: Surnames, Reproductive Success, Genetic Selection and Social Class in Pre-Industrial

England,” Jan. 19, 2009, www.econ.ucdavis.edu/faculty/gclark/Farewell%20to%20Alms/Clark%20-Surnames.pdf.10. Ron Unz, “How Social Darwinism Made Modern China: A Thousand Years of Meritocracy Shaped the Middle Kingdom,” The

American Conservative, Mar. 11, 2013, www.theamericanconservative.com/articles/how-social-darwinism-made-modern-china-248.

11. Toby E. Huff, The Rise of Early Modern Science: Islam, China, and the West, 2d ed. (New York: Cambridge University Press,2003), 282.

12. Marta Mirazón Lahr, The Evolution of Modern Human Diversity: A Study of Cranial Variation (Cambridge, UK: CambridgeUniversity Press, 1996), 263.

13. Marta Mirazón Lahr and Richard V. S. Wright, “The Question of Robusticity and the Relationship Between Cranial Size and Shapein Homo sapiens,” Journal of Human Evolution 31, no. 2 (Aug. 1996): 157–91.

14. Richard Wrangham, interview, Edge.org, Feb. 2, 2002.15. Norbert Elias, The Civilizing Process: Sociogenetic and Psychogenetic Investigations (Oxford, UK: Blackwell, 1994), 167.16. Steven Pinker, The Better Angels of Our Nature: Why Violence Has Declined (New York: Viking, 2011), 48–50.17. Ibid., 60–63.

18. Ibid., 149.19. Ibid., 613.20. Ibid., 614.21. Jonathan Gibbons, ed., 2011 Global Study on Homicide: Trends, Context, Data (Vienna: United Nations Office on Drugs and

Crime, 2010).22. Philip Carl Salzman, Culture and Conflict in the Middle East (Amherst, NY: Humanity Books, 2008), 184.23. Arab Human Development Report 2009: Challenges to Human Security in the Arab Countries (New York: United Nations

Development Programme, Regional Bureau for Arab States, 2009), 9.24. Ibid., 193.25. Martin Meredith, The Fate of Africa: A History of Fifty Years of Independence (New York: PublicAffairs, 2005), 682.26. Richard Dowden, Africa: Altered States, Ordinary Miracles (New York: PublicAffairs, 2009), 535.27. Shantayanan Devarajan and Wolfgang Fengler, “Africa’s Economic Boom: Why the Pessimists and the Optimists Are Both Right,”

Foreign Affairs, May–June 2013, 68–81.28. Clark, Farewell to Alms, 259–71.29. Pomeranz, Great Divergence, 297.30. Daron Acemog˘lu and James A. Robinson, Why Nations Fail: The Origins of Power, Prosperity, and Poverty (New York:

Crown, 2012), 73.31. Lawrence E. Harrison and Samuel P. Huntington, eds., Culture Matters: How Values Shape Human Progress (New York: Basic

Books, 2000), xiii.32. Jeffrey Sachs, “Notes on a New Sociology of Economic Development,” in Harrison and Huntington, Culture Matters, 29–43 (41–42

cited).33. Nathan Glazer, “Disaggregating Culture,” in Harrison and Huntington, Culture Matters, 219–31 (220–21 cited).34. Daniel Etounga-Manguelle, “Does Africa Need a Cultural Adjustment Program?” in Harrison and Huntington, Culture Matters, 65–

77.35. Lawrence E. Harrison, The Central Liberal Truth: How Politics Can Change a Culture and Save It from Itself (Oxford, UK:

Oxford University Press, 2006), 1.36. Thomas Sowell, Migrations and Cultures: A World View (New York: Basic Books, 1996), 118.37. Ibid., 192.38. Ibid., 219.39. Sowell, Conquests and Cultures, 330.40. Sowell, Migrations and Cultures, 226.41. Ibid., 57.42. Christopher F. Chabris et al., “Most Reported Genetic Associations with General Intelligence Are Probably False Positives,”

Psychological Science 20, no. 10 (Sept. 24, 2012): 1–10.43. Richard Lynn and Tatu Vanhanen, IQ and Global Inequality (Augusta, GA: Washington Summit, 2006), 238–39.44. Ibid., 2.45. Ibid., 277.46. Ibid., 281.47. Acemog˘lu and Robinson, Why Nations Fail, 48.48. Ibid., 238.49. Ibid., 454.50. Ibid., 211.51. Ibid., 427.

CHAPTER 8: JEWISH ADAPTATIONS

1. Gertrude Himmelfarb, The People of the Book: Philosemitism in England, from Cromwell to Churchill (New York: EncounterBooks, 2011), 3.

2. Charles Murray, “Jewish Genius,” Commentary, Apr. 2007, 29–35.3. Melvin Konner, Unsettled: An Anthropology of the Jews (New York: Viking Compass, 2003), 199.4. Harry Ostrer, Legacy: A Genetic History of the Jewish People (New York: Oxford University Press, 2012), 92–93.5. Anna C. Need, Dalia Kasparaviciutè, Elizabeth T. Cirulli and David B. Goldstein, “A Genome-Wide Genetic Signature of Jewish

Ancestry Perfectly Separates Individuals with and without Full Jewish Ancestry in a Large Random Sample of EuropeanAmericans,” Genome Biology 10, Issue 1, Article R7, 2009.

6. Gregory Cochran, Jason Hardy, and Henry Harpending, “Natural History of Ashkenazi Intelligence,” Journal of Biosocial Science38, no. 5 (Sept. 2006): 659–93.

7. Maristella Botticini and Zvi Eckstein, The Chosen Few: How Education Shaped Jewish History, 70–1492 (Princeton, NJ:Princeton University Press, 2012), 109.

8. Ibid., 193.9. Ibid., 267.10. Konner, Unsettled, 189.11. Neil Risch et al., “Geographic Distribution of Disease Mutations in the Ashkenazi Jewish Population Supports Genetic Drift over

Selection,” American Journal of Human Genetics 72, no. 4 (Apr. 2003): 812–22.12. See, for instance, Nicholas Wade, The Faith Instinct: How Religion Evolved and Why It Endures (New York: Penguin Press,

2010), 157–72.13. Botticini and Eckstein, Chosen Few, 150.14. Jerry Z. Muller, Capitalism and the Jews (Princeton, NJ: Princeton University Press, 2010), 88.

CHAPTER 9: THE RISE OF THE WEST

1. William H. McNeill, A World History (New York: Oxford University Press, 1967), 295.2. Victor Davis Hanson, Carnage and Culture: Landmark Battles in the Rise to Western Power (New York: Random House, 2001),

5.3. Niall Ferguson, Civilization: The West and the Rest (London: Allen Lane, 2011), 18.4. Toby E. Huff, Intellectual Curiosity and the Scientific Revolution: A Global Perspective (Cambridge, UK: Cambridge University

Press, 2011), 126.5. Ibid., 133.6. Quoted in ibid., 110.7. Jared Diamond, Guns, Germs, and Steel: The Fates of Human Societies (New York: Norton, 1997), 25.8. Ibid., 219. IQ for Papua New Guinea is 83, compared with the European normalized score of 100. Richard Lynn and Tatu Vanhanen, IQ and

Global Inequality (Augusta, GA: Washington Summit, 2006), 146. If Diamond has in mind some more appropriate measure ofintelligence, he does not cite it.

10. Mark Elvin, The Pattern of the Chinese Past (Palo Alto, CA: Stanford University Press, 1973), 297–98, quoted in David S. Landes,The Wealth and Poverty of Nations: Why Some Are So Rich and Some So Poor (New York: Norton, 1998), 55.

11. Ferguson, Civilization, 13.12. Ibid., 256–57.13. Eric Jones, The European Miracle: Environments, Economies, and Geopolitics in the History of Europe and Asia (Cambridge,

UK: Cambridge University Press, 2003), 61.14. Ibid., 106.15. Quoted in ibid., 153.16. Jones, European Miracle, 61.17. Huff, Intellectual Curiosity, 128.18. Timur Kuran, The Long Divergence: How Islamic Law Held Back the Middle East (Princeton, NJ: Princeton University Press,

2011), 281.19. Toby E. Huff, The Rise of Early Modern Science: Islam, China, and the West (Cambridge, UK: Cambridge University Press,

2003), 47.20. Ibid., 321.21. Ibid., 10.22. David S. Landes, The Wealth and Poverty of Nations: Why Some Are So Rich and Some So Poor (New York: Norton, 1998), 56.23. Lecture in 1755, quoted in Dugald Stewart, “Account of the Life and Writings of Adam Smith LL.D.,” Transactions of the Royal

Society of Edinburgh, Jan. 21 and Mar. 18, 1793, section 4, repr. in Collected Works of Dugald Stewart, ed. William Hamilton(Edinburgh: Thomas Constable, 1854), vol. 10, 1–98.

24. Landes, Wealth and Poverty, 516.

CHAPTER 10: EVOLUTIONARY PERSPECTIVES ON RACE

1. This image is derived from an idea of Richard Dawkins that relates human and chimp ancestry.2. Niall Ferguson, Civilization: The West and the Rest (London: Allen Lane, 2011), 322.

INDEX

The page numbers in this index refer to the printed version of this book. The link provided will take you to the beginning of that printpage. You may need to scroll forward from that location to find the corresponding reference on your e-reader.

Abbasid empire, 212–13ABCC11 gene, 90–91, 121absolutist regimes, 195, 237Acemoglu, Daron, 148–49, 175, 180, 193–96Aché, 156adaptation, 58, 64Afghanistan, 148, 241Africa, 85, 100–102, 137, 147, 172, 184, 197, 225

Bantu expansion in, 84–85, 100, 101foreign aid to, 13, 148, 175, 181, 183GNP in, 176government and ruling elites in, 175–76human dispersal from, 1–2, 76, 80, 84, 85, 93, 225kingdoms in, 134–35lactose tolerance and, 61populations in, 181, 226, 248transition to modern economy in, 180–82tribalism in, 173, 175, 177, 181violence in, 176

African Americans, 4, 94IQ tests and, 189–91MAO-A promoters in, 56–57physical characteristics in, 88

Africans, 2, 4, 18, 20, 93, 94, 98, 109IQ tests and, 191physical characteristics in, 87–91skulls of, 70society of, 123–24

aggression, 53–57, 62, 82, 130, 131, 132, 170–71, 241, 243, 244genes and, 54–57, 110, 170–71

agriculture, 11, 50, 62, 63, 80, 81–82, 84–85, 100, 110, 129, 132, 139, 149, 152, 153, 163, 195, 197, 221, 226AIMs (ancestry informative markers), 70, 115–16Akey, Joshua M., 108alleles, 71–75, 76, 87–92, 95–96, 98, 102, 103–4, 107, 114, 172

diseases and, 114–15, 206Duffy null, 110, 114, 115hard and soft sweeps of, 110–14intelligence and, 190

Allen, Robert, 31American Anthropological Association, 5, 119, 121American Association of Physical Anthropologists, 121American Indians, see Native AmericansAmerican Sociological Association, 5Americas, 85, 225, 226, 233Anatolia, 84Andean highlands, 8, 226anthropologists, physical, 69–70, 82ants, 65–66

apes, see monkeys and apesapocrine glands, 89, 91Arab world, 174–75, 182

science in, 228–32see also Islamic world

Arctic regions, 134, 214Aristotle, 231Arkwright, Richard, 158Aryans (Indo-Europeans), 19–20Ashkenazim, 199–209, 214Asian Americans, IQ tests and, 189–90astronomy, 215–19, 228athleticism, 8Australia, 93, 94, 222, 225–26autocracies, 9, 237Aztecs, 226

Bacon, Francis, 228Baibars, 143Bantu expansion, 84–85, 100, 101behavior:

individual, institutions’ effect on, 147–49social, see social behaviors

Belyaev, Dmitriy, 54, 160–61Beringia, 81, 134Binet, Alfred, 30Black, Edwin, 29, 35Black Death, 153Bloom syndrome, 208Blumenbach, Johann, 18–19, 86Boas, Franz, 5–6, 31–32, 69, 241bone, see skeletonBotticini, Maristella, 151, 209–10, 211, 212Bowcock, Anne, 97brain, 4, 51, 106, 108, 109, 208

oxytocin in, 51–53, 243size of, 21, 50

Brazil, 186BRCA1 and BRCA2 genes, 208breast cancer, 208breasts, 89, 90Buck, Carrie, 29Buck v. Bell, 29–30, 31bureaucracy, 140, 173Burusho, 98bushmen, 17Byzantine empire, 174–75, 182, 234

Cambodia, 187Carnegie Institution, 28–29, 34, 38Carneiro, Robert, 133Castle, William E., 29Caucasians, 4, 86, 93, 94, 96, 246

invention of word, 18–19MAO-A promoters in, 56–57physical characteristics in, 87skulls of, 70split between East Asians and, 86

transition to modern economy by, 178Caucasus, 18, 86Cavalli-Sforza, Luca, 97Chagnon, Napoleon, 131Chapais, Bernard, 39–66, 44, 45Charlemagne, 234, 246Charles I, King, 146chemokines, 110chiefdoms, 133, 134childbirth:

age at first reproduction, 3risk of death in, 162

chimpanzees, 41–47, 110, 242cooperation in, 47–48kinship and, 43–44

China, 12, 17, 85, 90, 132, 134, 135, 137, 172, 189, 193, 195, 219, 220, 224, 227–28, 233–38, 244, 246–48, 250education system in, 231evolutionary changes in, 165–66inheritance practices in, 165one child policy in, 180population increase in, 165rule of law and, 144–45science in, 228–32state achieved in, 137–42, 144technology in, 234telescope introduced to, 215–16, 217–19transition to modern economy in, 178–79, 180

Chinese, 4, 89, 91, 92, 147Han, 84, 88, 90immigrants, 186–87, 188, 201, 213, 237intelligence tests and, 166society of, 123–24

Christianity, 211, 212, 217, 232Protestantism, 126

chromosomes, 106, 107, 116Y, 74–75, 78, 163

Churchill, Winston, 33civilizations, formation of, 132–35Clark, Gregory, 151–55, 158–64, 171–73, 178–79, 184–85, 236click-speakers, 17, 100–101, 102climate, 223, 246

change in, 80, 83, 248clines, 98–99clothing, 108–9Cochran, Gregory, 202–5, 207–9, 214Collins, Francis, 68Columbus, Christopher, 233competition, 224conformity, 59, 241, 245

see also social normsCongo, 176continental drift, 6cooperation:

among chimpanzees, 47–48in human societies, 47–50, 51, 62, 124, 132, 243

Copernicus, Nicolaus, 216, 217Coyne, Jerry, 68crime, 50

see also violenceCrusades, 204culture(s), 5–6, 9, 241–42, 245

economics and, 13, 155, 183–85equality of, 6, 9genes and, 58, 59–61race and, 184, 185in social institutions, 124–27

DARC gene, 110–11Darwin, Charles, 11, 22–23, 24, 26, 39, 67, 95, 164, 245

The Descent of Man, 22Malthus and, 155On the Origin of Species, 16, 22Social Darwinism and, 24–25

Davenport, Charles, 28, 29, 30, 33–34, 35, 38De Dreu, Carsten, 51–52delayed gratification and patience, 157–58, 160, 184–85Deng Xiaoping, 179Denmark, 13Descent of Man, The (Darwin), 22Devarajan, Shantayanan, 176Diamond, Jared, 68, 117–18, 221–23diet, 60, 108

lactase and, 60–61, 113disciplined behaviors, 158, 183diseases, 108, 110–11, 116, 223

alleles and, 114–15, 206malaria, 110–11, 116, 117–18, 206Mendelian, 202, 205–8, 209sickle-cell anemia, 111, 116, 206thalassemia, 111, 118

DNA, 14, 56, 70, 72–74, 96, 109, 113AIMs (ancestry informative markers) and, 70, 115–16bases of, 72–73, 79, 88coding, 73complementary, 79fingerprinting of, 104–7, 116mitochondrial, 74, 79repair systems of, 208repeats in, 96, 97, 99, 100, 102, 116

dogs, 167domestication:

in animals, 160–61, 167–68in humans, 160–61, 167–73

dopamine, 55Dowden, Patrick, 176Duffy null allele, 110, 114, 115

earwax, 90–91, 92, 121East, Edward M., 29East Asians, 2, 4, 18, 20, 86, 93, 94, 109, 110, 147, 177–79, 182, 188, 193, 220, 223, 225, 236, 246, 248, 249

IQ tests and, 8, 191physical characteristics in, 87–92skulls of, 70split between Caucasians and, 86

eccrine glands, 89, 91Eckstein, Zvi, 151, 209–10, 211, 212

economic development, 182–89economics, economies, 10, 172, 224, 244, 247

culture and, 13, 155, 183–85disparities in, 13–14and escape from tribalism and poverty, 177–82human nature and, 154–58, 160, 161Industrial Revolution and, see Industrial RevolutionIQ and wealth hypothesis, 189–93market, 161wealth and, see wealth

EDAR-V370A gene, 89–90, 92, 105, 118, 121education, 191, 199

Head Start and, 190Edwards, A.W.F., 120egalitarianism, 63, 128, 129, 173eggs, 106Egypt, 132, 134, 143–44Elias, Norbert, 123, 168–70Elvin, Mark, 223empathy, 170empires, 234, 246–47England, 137, 152, 237

behavior changes in, 155–58, 160, 161economy in, 162ethnic prejudices and, 17farm laborers’ wages in, 152–53Glorious Revolution in, 194–95, 196, 224Industrial Revolution in, 151–52, 158–59, 162, 163, 172, 178–79, 185, 193–95population growth in, 162social mobility in, 164

Enlightenment, 154environment, societal change and, 57–61Equatorial Guinea, 189Erasmus, 168Eskimos, 134, 214Essay on the Inequality of Human Races, An (Gobineau), 19–20Essay on the Principle of Population, An (Malthus), 152, 153–54, 155, 162Ethiopia, 195ethnic prejudice, 17, 19

racism vs., 17etiquette, 168Etounga-Manguelle, Danielle, 184, 185eugenics, 16, 18, 26–38

in Germany, 35–37immigration and, 31intelligence tests, 30sterilization and, 27–31, 33–38

Eugenics Record Office, 28, 34Eugenics Research Association, 29Eugenics Society, 33Eurasia, 77, 86, 147, 226Europe:

awakening of, 12–13colonization by, 18, 147, 177, 226, 247educational institutes in, 231–32empires in, 234, 246–47exploration by, 233, 234internal wars in, 233–34

in Middle Ages, 227–28religion in, 145–46states achieved in, 137, 138, 140–41, 142, 144, 146telescope introduced to, 215–16, 219tribalism in, 137, 144, 145, 147see also West

European Americans, IQ tests and, 189–90Europeans, 2, 4, 9, 18, 20, 86, 93, 109, 110, 147, 182, 219, 223, 225, 236

ethnic prejudices among, 17genetics of, 79–80IQ tests and, 8, 191, 192physical characteristics in, 87–91society of, 123–24transition to modern economy by, 178, 188

evolution:Darwin’s theory of, 22, 26pedomorphic, 167speciation and, 71–75, 76

evolution, human, 1–2belief in recent suspension of, 5genes changed in, 2–3history and, 245–49of independent populations, 1–2natural selection in, see natural selectionnew view of, 2–4races and, 71–75as recent, copious and regional, 2–4, 6, 7, 10, 242, 243, 251social science and, 5, 241societies created through, 65–66

evolutionary perspectives on race, 239–51evolutionary stresses, 80–85executions, 168–69eyes, whites of, 39–40

face recognition, 52Fanconi’s anemia, 208Feldman, Marcus, 97–99Fengler, Wolfgang, 176Ferguson, Niall, 215, 224–25, 246feudalism, 145, 146Finns, 57, 94First Crusade, 204fossils, 107, 167foxes, 160–61founder effect, 206–7FOXP2 gene, 110Framington Heart Study, 3France, 137, 140

ethnic prejudices and, 17Fukuyama, Francis, 136, 137, 139, 142, 144–49, 172–73, 193, 243Funnel Beaker Culture, 61, 113

Galileo, 216, 217Galton, Francis, 25–27, 33, 34Gama, Vasco da, 233Gaucher’s disease, 206, 209gene(s), 54, 95, 250–51

ABCC11, 90–91, 121

aggression and, 54–57alleles of, see allelesBRCA1 and BRCA2, 208chips, 79culture and, 48, 59–61DARC, 110–11EDAR-V370A, 89–90, 92, 105, 118, 121evolutionary changes in, 2–3FOXP2, 110HTR2B, 57KITLG, 111lactase, 60–61, 113MAO-A, 54–57, 110, 170–71, 243, 244MC1R, 87–88physical characteristics and, 87–92promoters of, 55–57race and, 95SLC24A5, 88, 111social behavior and, 9, 41, 46–47, 50–51, 53, 57–59, 64, 85

gene-culture evolution, 59–60genetic determinism, 221–22genetic diversity, species origin and, 102genetic drift, 72–75, 76, 78, 102–3, 114, 196genetic gradients (clines), 98–99genetics:

language families and, 101Mendel’s laws of, 28, 29, 34of race, 95–122in social institutions, 124–27

genetic structure of race, 114–17genome, human, 1, 2, 14, 68, 251

association studies and, 114–15clusters of variation in, 96–102fingerprints of selection in, 102–10tandem repeats in, 96, 97, 99, 100

genomics, racial differences and, 7–9genotypes, 75, 109geographic determinism, 221–25geography, 223Germans:

ethnic prejudices and, 17immigrants, 187–88

Germany, 135, 137, 236–37IQ tests in, 192Nazi, see Nazi Germany

Ghana, 183Gillham, Nicholas, 26–27glaciers, 81Glazer, Nathan, 184Glorious Revolution, 194–95, 196, 224Gobineau, Joseph-Arthur Comte de, 19–20Gould, Stephen Jay, 21–22government(s), 148, 173

absolutist, 195, 237in Africa, 175–76kleptocracies, 175in Middle East, 174

gracilization, 82, 167–68, 170

Grant, Madison, 31–33Greece, ancient, 17, 228, 229Gregory VII, Pope, 145–46guilt, 50Guns, Germs, and Steel (Diamond), 117–18, 221–23

hair, 88–89, 90, 92, 105, 108, 118, 236, 250Haiti, 13, 189, 241Hanson, Victor Davis, 215HapMap, 103Hapsburgs, 234, 247Harappan civilization, 134Hardy, Jason, 202–5, 207–9, 214Hargreaves, James, 158–59Harpending, Henry, 202–5, 207–9, 214Harriman, E. H., 28Harriman, Mary, 28Harrison, Lawrence, 185Hawaii, 134, 186Head Start, 190height, 112–13Henry IV, King, 146Heron, David, 34high altitudes, 3, 8, 107, 214Himmelfarb, Gertrude, 198history:

evolution and, 245–49social behavior and, 9–13, 135–46

Hitler, Adolf, 16, 19–20, 33, 34–37, 135, 234, 247Mein Kampf, 33

Hofstadter, Richard, 16Holmes, Oliver Wendell, 29–30Holocaust, 31, 36–37, 69, 198homicide, 156, 170, 172Homo erectus, 77Homo ergaster, 46HTR2B, 57Huff, Toby, 166, 216, 217, 219, 228, 230–31, 232human capital, 191human nature, 150–97, 244

domestication and, 160–61, 167–73economics and, 154–58, 160, 161and changes in China, 165–66see also social behaviors

Hung-wu, 230hunter-gatherer societies, 62, 76–78, 84, 100–101, 136, 178, 197, 223, 242–43

division of labor in, 129egalitarianism in, 63, 128, 129and formation of civilizations, 133initiation rites in, 130institutions of, 128kinship in, 44, 130punishment in, 49religion in, 130–31time preferences in, 158transition to settled life from, 10–11, 50, 58, 62–63, 82, 85, 110, 127–32, 149, 167, 226violence in, 156

hunting, 62

Huntington, Samuel, 183

ice ages, 77, 91, 93Pleistocene, 76, 81, 83

Iceland, 13, 94immigrants, immigration, 28, 38, 188

Chinese, 186–87, 188, 201, 213, 237eugenicists and, 31German, 187–88Japanese, 185–86, 188

Immigration Act, 31, 33Incas, 134, 226incest, 237, 250–51India, 134, 147, 227, 233, 246

Brahmanism in, 141state achieved in, 137, 141–42telescope introduced to, 215–17

Indian subcontinent, 4, 86, 96transition to modern economy in, 178

Indonesia, 18, 187Indo-Europeans (Aryans), 19–20Industrial Revolution, 12, 149, 151–52, 154, 158–59, 161–63, 172, 178–79, 185, 188, 193, 203, 222–24, 244influenza, 116Inquisition, 216institutional drift, 196institutions, see social institutionsintelligence, 7–8, 111–12, 204, 214, 222–23

alleles and, 190brain size and, 21in Jewish populations, 199, 201–5, 207–14tests of, see IQ tests

intentionality, shared, 48, 49interbreeding, 17, 19, 23, 71, 75, 78, 84, 116interest rates, 157, 158IQ and Global Inequality (Lynn and Vanhanen), 191IQ and the Wealth of Nations (Lynn and Vanhanen), 191IQ tests, 8, 191, 214, 223

Ashkenazi Jews and, 202, 214Chinese and, 166debate between hereditarians and environmentalists on, 189–91eugenicists and, 30wealth and, 189–93

Iraq, 14, 148, 212, 213, 241Isaac, Benjamin, 17–18Islam, 229, 230Islamic world, 12, 219, 228, 234, 244, 246

military slavery in, 142–44science in, 228–32state achieved in, 137

Jahangir, 216James II, King, 146, 194Janissaries, 143, 144Japan, 13, 88, 90, 172, 193, 196, 220, 236–37, 246, 248transition to modern economy in, 178–79

Japanese, 4, 91, 166immigrants, 185–86, 188

Jennings, Herbert S., 29

Jensen, Arthur, 190Jesuits, 217, 218Jews, 94, 187, 197, 198–214, 244, 249

achievements of, 198–99, 202, 214Ashkenazi, 199–209, 214Christian conversion among, 211discrimination against, 36–37, 198, 213expulsions and massacres of, 201, 204–5, 210Gobineau’s views on, 19–20Hitler and, 19–20Holocaust and, 31, 36–37, 69, 198intelligence of, 199, 201–5, 207–14literacy and, 202, 210–12marriage and, 199–200, 204, 205Mendelian diseases and, 202, 205–8, 209moneylending and, 202–5, 210, 212, 213occupations of, 212, 213Oriental (Mizrahi), 200–201, 204, 209population of, 211, 213reproductive success of, 203Sephardi, 200–201, 204, 206, 209standards of living of, 203Talmud and, 205, 211, 212Torah and, 210–11trade and, 212, 213, 214

Jones, Eric, 225Jordan, Winthrop, 72Joshua ben Gamla, 210Journal of Biosocial Science, 202Judaism, 210–11

Kamehameha, King, 134Kant, Immanuel, 37Kapital, Das (Marx), 24Kaplan, Hillard, 63Kepler, Johannes, 216, 217Kevles, Daniel, 29, 30Khoisan, 101Kim family, 189kinship, 136, 143, 178

chimpanzees and, 43–44in hunter-gatherer societies, 44, 130

KITLG gene, 111kleptocracy, 175Konner, Melvin, 205Korea, Koreans, 4, 90, 166, 179–80, 193, 246Korean War, 220Kuran, Timur, 230

lactase gene, 60–61, 113lactose tolerance, 60–61Landes, David, 235–36language(s), 40, 83–84, 92, 98

cultural component of, 125genetics and, 101grammar in, 125Indo-European, 84Khoisan, 101

in New Guinea, 83, 84in United States, 83

Laos, 187Last Glacial Maximum, 81law, 58, 124–25, 144–45, 146, 194, 224, 232, 237, 247

canon, 146Justinian code, 146

Lazarus, Emma, 32Lebanon, 182Lewontin, Richard, 118–20Lewontin’s fallacy, 120Li, Jun Z., 99lice, 22–23, 108–9Lippershey, Hans, 215–16L’Isle-aux-Coudres, 3literacy, 156–57, 160, 175, 180, 229, 236, 244

Jews and, 202, 210–12Little, Clarence, 29Livingstone, Frank, 98Lynn, Richard, 191–93Lysenko, Trofim, 160

madrasas, 229malaria, 110–11, 116, 117–18, 206Malaya, 18Malaysia, 186Malthus, Thomas, 11, 159, 161, 163–65, 172, 178, 181, 197, 245

Darwin and, 155An Essay on the Principle of Population, 152, 153–54, 155, 162

Malthusian trap, 149, 152, 153–54, 162, 179, 203, 222Mamluks, 143–44Man’s Most Dangerous Myth: The Fallacy of Race (Montagu), 69, 119MAO-A gene, 54–57, 110, 170–71, 243, 244Mao Tse-tung, 135, 145, 189marriage, 145, 154, 162–63

incest and, 237intermarriage, 17, 19, 23, 71, 75, 78, 84, 92, 116, 199Jews and, 199–200, 204, 205local, 80

Marshall Plan, 183marshmallow test, 157–58Marx, Karl, 24Marxism, 27, 59, 201mate guarding, 44–45MC1R gene, 87–88McNeill, William, 215medicine, 221, 224Mein Kampf (Hitler), 33Mendel, Gregor, 28, 29, 34Mendelian diseases, 202, 205–8, 209menopause, age at first, 3Mental Deficiency Act, 33Meredith, Martin, 175–76Mesoamerica, 134Meso-Industrial Age, 196–97Mesolithic Age, 197Mesopotamia, 132, 226middle-class culture, 160, 161, 171, 172

Middle East, 86, 96, 137, 177, 197, 230transition to modern economy in, 178tribalism in, 173, 174–75, 177

migrations, 72, 75, 76, 185–86military, 58, 63, 64, 130, 148, 247military power, 220, 234military slavery, 142–44milk consumption, 60–61mind as blank slate, 59, 201, 242Mirazón Lahr, Marta, 167Mischel, Walter, 157–58Mismeasure of Man, The (Gould), 21mitochondria, 74, 79Mizrahim (Oriental Jews), 200–201, 204, 209Moche state, 134moneylending, 202–5, 210, 212, 213Mongoloid skulls, 91Mongols, 136, 141, 246, 247monkeys and apes, 39

chimpanzees, see chimpanzeesmonogamy, 45Montagu, Ashley, 69, 70, 119moral dilemmas, 52morality, 50, 59, 124Morton, Samuel, 20–22mosaic zones, 83, 84mucolipidosis type IV, 206Muhammad, 229Muller, Jerry Z., 213Muslim world, see Islamic worldmutations, 72, 73, 75, 78Myers, Richard M., 99

Napoleon I, Emperor, 234, 247Narmer, 134national character, 150–51National Human Genome Research Institute, 68National Institutes of Health, 103Native Americans, 18, 20, 88, 91, 93, 94Natufian culture, 82natural selection, 1, 2–4, 11, 72, 73, 75, 76, 78, 114, 155, 222, 243–44, 245

diversity reduction and, 102fingerprints of, in human genome, 102–10human social behavior and, 40, 41, 66MAO-A gene and, 55, 56neutral variations in, 102purifying, 73, 87–88trust and, 53whites of the eyes and, 40

nature vs. nurture, 26Nazi Germany, 16, 25, 34–35

eugenics program in, 35–37Holocaust and, 31, 36–37, 69, 198

Neanderthals, 77Near East, 4, 85, 182, 227Neolithic Age, 197nervous system, 109neurotransmitters, 54–55

New Guinea, 83, 84, 93, 94, 222Newton, Isaac, 216Niemann-Pick disease, 206Nigeria, 13, 176Noah’s ark, 18Nordics, 31, 32, 35, 37norepinephrine, 54–55North, Douglass, 124, 136, 243North Korea, 13, 179–80, 189Nuremberg Law, 36

Ögedei Khan, 234Olmec state, 134Olympic Games, 8On Civility in Children (Erasmus), 168On the Natural Variety of Mankind (Blumenbach), 18–19On the Origin of Species (Darwin), 16, 22Oriental Jews (Mizrahim), 200–201, 204, 209Ottomans, 144, 147, 174, 175, 182, 220, 229, 230, 233, 234, 247

telescope introduced to, 215–16, 217oxytocin, 51–53, 243ovarian cancer, 208

pair bonding, 44–45, 46Paleolithic Age, 197, 222Passing of the Great Race, The (Grant), 31, 33pastoralists, 63patience and delayed gratification, 157–58, 160, 184–85Paul of Tarsus, 211Pearl, Raymond, 29pedomorphic evolution, 167peopling of the world, 76–80, 84Persia, 212, 213Peru, 186Pharisees, 210phenotypes, 75, 109physical anthropologists, 69–70, 82physical characteristics, genes and, 87–92Pinker, Steven, 169–72plagues, 153Pleistocene Ice Age, 76, 81, 83Polynesia, 134Pomeranz, Kenneth, 154, 179population, 11, 245, 246

budding, 76in evolution of societies, 132–34increases in, 64, 83, 85major splits in, 85–86, 93Malthusian trap and, 149, 152, 153–54, 162, 179, 203, 222movements of, 80–81peopling of the world, 76–80and transition to settled life from hunter-gatherer societies, 128–29

poverty, escape from, 177–82primates, 242

chimpanzees, see chimpanzeesprinting presses, 229, 231Pritchard, Jonathan, 103, 105, 106, 109, 111, 112property rights, 194, 224, 237

Protestantism, 126Ptolemaic system, 216, 217punishment, 49–50, 57–58, 124, 125, 238, 243

in hunter-gatherer societies, 49self-, 125

pygmies, 101, 112–13

Qur’an, 229

race(s):agreement for existence of, 69AIMs (ancestry informative markers) and, 70, 115–16arguments against existence of, 117–22biological basis for, 4, 5, 68classification of, 18–23, 92–94, 119, 121as clusters of variation, 96–102culture and, 184, 185denial of existence of, 67–68, 70, 91distinct boundaries lacking between, 121evolution and, 71–75evolutionary perspectives on, 239–51five continental, 92–94, 96, 97–98, 100genes and, 95genetics of, 95–122genetic structure of, 114–17interbreeding and, 17, 19, 23, 71, 75, 78, 92political agendas and, 37, 68–69, 201separate creation of, 20, 21as separate species, 20, 22–23as social construct, 5, 68, 119social scientists’ view of, 5speciation and, 71–75, 76three principle, 2, 4understanding, 249–51

Race? Debunking a Scientific Myth (Tattersall and DeSalle), 67–68racial differences, genomics and, 7–9racism, 17–18, 120, 201, 222, 250

emergence of, 17, 18ethnic prejudice vs., 17fear of promoting, 2, 6, 10, 249, 251hierarchy of races in, 17opposition to, 7

Rambam Health Care Center, 56rats, 54reason, 232recombination, 106religion, 50, 63, 124–26, 130–31, 142, 231, 232

Christianity, see Christianityin European institutions, 145–46in hunter-gatherer societies, 130–31Islam, 229, 230Judaism, 210–11

religious office, 133reproduction, age at first, 3Ricci, Matteo, 217–18Risch, Neil, 97, 207Robinson, James, 148–49, 175, 180, 193–96Rockefeller Foundation, 28–29, 38

Roman empire, 140, 141, 201Roosevelt, Theodore, 29Rosenberg, Noah, 97–99rule following, 49, 57, 124, 125, 188, 238, 243

see also lawRussia, 135, 187, 220, 229, 246

Sabeti, Pardis, 105Sachs, Jeffrey, 183–84Sahul, 76, 93Saint Louis University, 56Salzman, Philip, 174Samuelson, Paul, 6saving and thrift, 156, 160, 172, 183, 184–85, 244Schall von Bell, Adam, 218science, 248, 249

astronomy, 215–19, 228in China, 228–32in Islamic world, 228–32perversions of, 16–38Western, 220, 222, 224, 228–32, 233, 234

Scientific Revolution, 216Selim I, Sultan, 229Sephardim, 200–201, 204, 206, 209serotonin, 54–55sexual selection, 86, 90, 91Shah Jahan, 216shame, 50, 125Shang Yang, 139, 140shared intentionality, 48, 49Shaw, George Bernard, 33Sherratt, Yvonne, 37Shih, Jean, 55sickle-cell anemia, 111, 116, 206Singapore, 13, 147, 148, 187skeletons, 106, 107, 108, 167

gracilization of, 82see also skulls

skin color, 41, 80–81, 85, 86–88, 92, 106, 108, 109–10, 111–12, 114, 118, 236, 250Skorecki, Karl, 56skulls, 70, 84, 118, 121

gracilization of, 167–68, 170Mongoloid, 91

slavery, 21, 170military, 142–44

SLC24A5 gene, 88, 111Smith, Adam, 235SNPs (single nucleotide polymorphisms), 79, 99–100, 102, 116, 200social behaviors, 109, 124, 236–37, 241–44, 246, 248–51

aggression and, see aggressionchanges in, 126chimpanzee society and, 41–47cooperation in, 47–50, 51, 62, 124, 243and development of large hierarchical organizations, 63, 83, 85economic progress and, 183–89environment and, 57–61evolution and, 65–66and expansion of populations and social structures, 64

eyes and, 39–40genes and, 9, 41, 46–47, 50–51, 53, 57–59, 64, 85genetically based, 126history and, 9–13, 135–46institutions’ effect on, 147–49modulation of, 185natural selection and, 40, 41, 66origins of, 39–66shaping of, 62–64and transition to settled life from hunter-gatherer societies, 127–32trust in, see trust

social cohesion, 126Social Darwinism, 16, 18, 24–25, 27, 37, 249social institutions, 14, 58, 59, 62, 63–64, 66, 123–49, 150, 236, 241, 242, 250

effects on social and individual behavior, 147–49genetics and culture blended in, 124–27history and, 135–46institutional drift and, 196longevity of, 126, 135, 150national failure and, 193–96transfer of, 14, 148, 241and transition to settled life from hunter-gatherer societies, 127–32

social norms, 49–50, 57, 58punishment for violating, 49–50, 57–58, 124, 125, 238, 243

social rank, 129–30descent in, 160, 163, 166mobility in, 164

social science, 4, 241human evolution and, 5race as viewed in, 5

societies, 123–49evolution of, 132–35

Sociobiology (Wilson), 59South America, 134, 246South Korea, 13, 179–80, 183, 189Soviet Union, 195Sowell, Thomas, 150, 185, 186–88species:

new, generation of, 71–75races as, 20, 22–23

Spencer, Herbert, 24sperm, 106sphingolipids, 206, 207–8spread zones, 83, 84–85Stalin, Joseph, 135Stanford University, 79states, formation of, 63, 133–35, 137–44, 178, 226, 245, 246

in China, 137–42, 144in Europe, 137, 138, 140–41, 142, 144, 146in India, 137, 141–42in Muslim world, 137

Stearns, Stephen, 3–4sterilization, 27–31, 33–38Stoneking, Mark, 108–9Suleiman the Magnificent, 12Sumerian civilization, 134Sunda, 91sundadonty, 91, 92

Supreme Court, U.S., 29–30, 31, 38surnames, 163–64survival of the fittest, 24sweat glands, 89, 90, 91

Taiwan, 13Talmud, 205, 211, 212Tasmania, 93Tay-Sachs disease, 206technology, 234, 248teeth, 89, 91, 92, 121

wisdom, 168telescopes, 215–19, 228Tempier, Étienne, 231Thailand, 88, 187thalassemia, 111, 118theory of mind, 48thrift and saving, 156, 160, 172, 183, 184–85, 244Tibetans, 3, 8, 84, 107, 214time preference, 157–58Tishkoff, Sarah, 100, 101Tomasello, Michael, 48, 49Torah, 210–11torture, 169, 170trade, 124–25, 180, 232–33, 247

Jews and, 212, 213, 214tribalism, tribal societies, 9, 10, 63, 64, 136–37, 142, 147–48, 173–77, 196–97, 223, 241

in Africa, 173, 175, 177, 181in China, 140, 142escape from, 177–82in Europe, 137, 144, 145, 147kinship in, 178lineage in, 136–37, 145in Middle East, 173, 174–75, 177

trust, 50–53, 57, 61, 62, 148, 178, 180, 184, 185, 189, 196–97, 241, 243, 245natural selection and, 53oxytocin and, 51–53, 243

twins, 54

Uigur Turks, 84, 94UNESCO, 69United Nations, 174University of Utah, 202–5, 207–9, 214universities, 231–32

politics and, 6–7Unz, Ron, 165, 192urbanization, 180, 188Ussher, James, 20

vaccination, 24–25, 30Vanhanen, Tatu, 191–93vasopressin, 53Vaughn, Michael, 56Venter, Craig, 68Vietnam, 187, 220villages, 132violence, 57, 156, 160, 168–71, 175, 189, 236, 244

to animals, 169

homicide, 156, 170, 172torture, 169, 170see also aggression

vitamin D, 86–87voles, 52–53

Wagner, Richard, 37walking upright, 44warfare, 64, 78, 80, 83, 124–25, 130–31, 132, 133, 169–70, 232, 245, 247wealth, 11–12, 83, 129–30, 148, 196

children and, 159–60, 166, 171–72, 203, 245IQ and, 189–93

Wealth and Poverty of Nations, The (Landes), 235–36weapons, 45Webb, Beatrice and Sidney, 33Weber, Max, 140“we” group, 48, 49West, 246–50

competing institutions in, 224dynamism of, 219–21geographic determinism and, 221–25military power of, 220as open society, 224–25, 232–35, 237, 247–48rise of, 12, 215–38, 244science in, 220, 222, 224, 228–32, 233, 234

West Africans, 8Western culture, 9Why Nations Fail (Acemoglu and Robinson), 148–49, 180, 193–96William of Orange, 152, 194Wilson, Edward O., 59witchcraft burnings, 170wolves, 167work, hours spent in, 157, 158work ethic, 156, 172, 183, 186, 188, 244World Bank, 176World War I, 35, 37World War II, 36, 38, 183, 220, 236Wrangham, Richard, 168Wright, Sewall, 120Wright’s fixation index, 118–19, 120Wu, Emperor, 166

Yang Guangxian, 219Yanomamö, 131Y chromosome, 74–75, 78, 163Yellow River valley, 226Yoruba, 111

Zheng He, 233

*Complementary here means that two strands of DNA carry sequences of DNA units that match each other at each pair of bases.Where one strand has A, the other has T at the same position, and where one strand has G, the other has C. Two such strands have ahigh chemical affinity for each other, which is weakened if even one pair of bases is not complementary.

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